A method and hoisting apparatus for hoisting a plurality of reliquefaction macro-units into an open hatch compartment

Abstract

The present application relates to a method for hoisting a large-scale reliquefaction equipment into an open cabin of an LNG ship, which comprises the following steps: first, adjusting ballast water to stabilize and balance the LNG ship; second, opening a hoisting hole on the top of the cabin; third, installing a shifting hoisting device in the cabin; fourth, a crane enters the large-scale reliquefaction equipment into the cabin through the hoisting hole, and slackens the hoisting rope into a shifting rope; fifth, lifting the hoisting rope to make the large-scale reliquefaction equipment leave the ground through the shifting rope in the cabin; sixth, shifting the large-scale reliquefaction equipment to the base by the shifting hoisting device; seventh, loosening the shifting rope, recovering the hook upward, removing the stabilizing lever and the shifting hoisting device, closing the hoisting hole, and completing the hoisting of the large-scale reliquefaction equipment. The method of the present application designs a special hoisting device to realize the cabin hoisting of the large-scale reliquefaction equipment after the completion of the construction, has the advantages of convenient installation and no time node limitation, and improves the shipbuilding efficiency and the dock utilization rate.

Description

Technical Field

[0001] This invention relates to shipbuilding, and more particularly to a process and specialized hoisting equipment for hoisting large reliquefaction equipment into open compartments on large LNG ships. Background Technology

[0002] In the installation and construction of LNG carriers, it is common to encounter situations where equipment arrives late, inconsistent with the ship's construction process. For example, if the reliquefaction system equipment arrives late, the compartment has already been built and construction of other parts has begun. In this case, it is necessary to drill holes in the compartment to hoist the reliquefaction equipment in. However, because other parts have already been installed, drilling holes for hoisting at this point is extremely difficult due to the large size of the equipment, and existing equipment is usually insufficient to meet the hoisting requirements.

[0003] Current methods involve creating large or multiple openings in the compartment to meet lifting requirements. However, this approach is generally not approved by shipowners as it affects shipbuilding progress and quality. Another existing method involves creating an opening in the top of the compartment at the middle location of multiple equipment bases requiring lifting. After the equipment is inserted, it is pulled manually using a hoist. However, due to the weight of the equipment, this makes it difficult to move and install it within the compartment. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method and hoisting equipment for hoisting multiple large reliquefaction units into an open chamber.

[0005] To achieve the above-mentioned objectives, the technical solution provided by this invention patent is as follows:

[0006] This invention first provides a method for hoisting a large-scale reliquefaction device into the open compartment of an LNG carrier. The large-scale reliquefaction device includes a reliquefaction control cabinet, a reliquefaction frequency converter control cabinet, and a reliquefaction system transformer. The hoisting method includes the following steps:

[0007] The first step is to adjust the ballast water to stabilize the LNG carrier, so that it can be smoothly docked at the pier, and to check its balance.

[0008] The second step is to locate the compartment where the large reliquefaction equipment needs to be hoisted. This compartment contains the equipment base for installing the large reliquefaction equipment, and hoisting holes are opened in the top of the compartment.

[0009] The third step is to install the transfer and hoisting equipment inside the cabin. The hoisting equipment includes a door support, a rope drum assembly, and a transfer rope. The door support includes vertical rods on both sides and a top beam. The vertical rods are fixed to both sides of the equipment base, and the beam is located directly above the equipment base. The rope drum assembly is installed on one side of the door support away from the hoisting hole. The rope drum assembly is equipped with outriggers, a rope drum, and an elastic telescopic gear. The two outriggers support the rope drum and the elastic telescopic gear, respectively. The transfer rope is wound around the rope drum and passes through the door support.

[0010] The fourth step involves connecting the crane hook to the lifting rings of the large reliquefaction equipment using lifting ropes. The equipment has four lifting rings at its four corners and a stabilizing grip in the center. Four lifting ropes are connected to the hooks and four lifting rings, with each rope forming a loop connecting the hook and the ring. The loop connection to the ring is fixed. The crane is then directed to lift the large reliquefaction equipment, entering the compartment through the lifting opening at the top. A stabilizing rod is then fixed at the opening of the lifting opening. Once the large reliquefaction equipment is lifted into the compartment... After the chamber is placed at the bottom, the hook on the crane continues to fall until the hook is inside the chamber. At this time, the four lifting ropes connected to the four lifting rings are all in a slack state. Pull the middle part of one side of the four lifting ropes toward the moving and lifting equipment, pass through the door bracket, and then wrap around the rope drum. Each loop rope is equipped with the lifting ring, rope drum and hook of the large reliquefaction equipment. The lifting rope connected to the moving and lifting equipment inside the chamber becomes the moving rope for moving the large reliquefaction equipment, and the moving rope near the bottom of the chamber is in a taut state.

[0011] Fifth step: Instruct the crane to initially lift the hoisting rope, so that the hoisting rope between the hook and the lifting ring becomes the upper displacement rope, close to the top crossbeam of the gantry and gradually taut. Continue to pull the crane upward. At this time, the hook will tilt towards the gantry and remain in a fixed position. The large liquefaction equipment will move vertically below the crane hook. At this time, the lower displacement rope is in a slack state. Start the rope drum and adjust the length of each displacement rope through the rope drum to convert the length of the lower displacement rope to the length of the upper displacement rope, so that the upper and lower displacement ropes are both in a taut state. At this time, the large liquefaction equipment will descend a certain height, but the four lifting rings will still be higher than the connection position between the lower displacement rope and the rope drum, and the hook will be on one side of the gantry.

[0012] Step 6: Slowly rotate the drum and stretch the lower displacement rope horizontally to slowly move the large reliquefaction equipment horizontally toward the gate support. At this time, the large reliquefaction equipment slowly falls. After the large reliquefaction equipment is moved to the gate support and is directly above the large equipment base, the position is determined. Then, release the hook on the crane downward and use the stabilizing grip on the large reliquefaction equipment to control the falling position until the large reliquefaction equipment is placed on the corresponding equipment base.

[0013] Step 7: Loosen the transfer rope connected to the lifting ring of the large reliquefaction equipment. The crane will retract the hook upwards, remove the stabilizing rod, disassemble the transfer and lifting equipment and take it out of the compartment. Then, seal the lifting hole on the top of the compartment to complete the lifting of the large reliquefaction equipment.

[0014] In the third step, the relocation and hoisting equipment includes a rope drum assembly. This assembly comprises outriggers, a first fixed plate, a second fixed plate, a third fixed plate, a fourth fixed plate, a rope drum, a power telescopic component, and elastic telescopic gears. The outriggers include a left outrigger and a right outrigger. The left outrigger connects to the second fixed plate, and the right outrigger connects to the first fixed plate. A fixed shaft is connected to one side of the middle of the second fixed plate, and multiple elastic telescopic gears are mounted on this shaft. The other end of the fixed shaft is fixed to the fourth fixed plate. A central shaft is connected to one side of the middle of the first fixed plate, and multiple power telescopic components are connected to the middle of this central shaft. The other end of the central shaft passes through the third fixed plate and connects to the fourth fixed plate. The third fixed plate has multiple locking holes, the positions of which correspond to the power telescopic components. The rope drum is fitted between the first and third fixed plates, and the power telescopic component is fitted inside the rope drum. A rotating motor is located outside the first fixed plate, and a limiting rotation component is located at the central shaft position inside the first fixed plate.

[0015] Furthermore, the right outrigger is first welded and fixed to the floor inside the cabin. After the displacement rope is wound around the rope drum, the left outrigger is then welded and fixed to the opposite position of the right outrigger inside the cabin, so that the elastic telescopic gear engages with the third fixed plate, and the elastic teeth on the elastic telescopic gear extend into the locking holes of the third fixed plate.

[0016] Furthermore, there are four sets of elastic telescopic gears fixed on the fixed shaft. The four sets of elastic telescopic gears are arranged in pairs facing each other. The four gears on the upper side of the elastic telescopic gears limit the telescopic length to the thickness of the third fixed disk. The four gears on the four sets of elastic telescopic gears that are in contact with the second fixed disk are elastically telescopic. The fixed shaft connecting the elastic telescopic gears is also elastically telescopic at the end that is in contact with the second fixed disk.

[0017] In the fourth step, the stabilizer bar is installed in the hoisting hole of the cabin. The stabilizer bar is located at the position of the maximum diameter of the circular opening. A limiting groove is provided in the middle of the stabilizer bar, and the hoisting rope of the crane is movably installed in the limiting groove.

[0018] In the fourth step, the lifting rings are placed at the four corners of the large reliquefaction equipment near the top. This arrangement is intended to facilitate the connection of the lifting ropes and to lower the center of gravity, thereby increasing stability.

[0019] In the fourth step, multiple buckles are installed on the looped rope. The length of the looped rope is selected by choosing one set of these buckles and attaching it to the lifting ring. These buckles are located at the lifting ring of the large reliquefaction equipment. The buckles serve a fixing function; while they control the length, they do not increase the overall length of the looped rope. However, by installing multiple buckles on four looped ropes and fixing multiple buckles on the same lifting ring, the length can be shortened, allowing for the same initial lifting length control as with all four looped ropes.

[0020] In the fourth step, the hoisting rope for the moving and lifting equipment passes through the lower part of the gantry bracket and is close to the top crossbeam.

[0021] In the fourth step, the displacement rope, which is looped on the rope drum, is wound for one and a half turns of the circumference of the rope drum.

[0022] To enable specialized hoisting of large-scale reliquefaction equipment in special environments, this invention also includes a specially designed relocation hoisting device. Structurally, it comprises a gantry frame, a rope drum assembly, and a relocation rope. The gantry frame includes vertical rods on both sides and a top beam. The vertical rods are fixed to both sides of the equipment base, and the beam is located directly above the equipment base. The rope drum assembly is installed on one side of the gantry frame away from the hoisting hole. This assembly includes support legs, a rope drum, and an elastic telescopic gear. The two support legs respectively support the rope drum and the elastic telescopic gear. The relocation rope is wound around the rope drum and passes through the gantry frame.

[0023] The rope drum assembly further includes support legs, a first fixed plate, a second fixed plate, a third fixed plate, a fourth fixed plate, and a power telescopic component. The support legs include a left support leg and a right support leg. The left support leg is connected to the second fixed plate, and the right support leg is connected to the first fixed plate. A fixed shaft is connected to one side of the middle of the second fixed plate. The fixed shaft is provided with multiple elastic telescopic gears, and the fourth fixed plate is fixed to the other end of the fixed shaft. One end of a central shaft is connected to one side of the middle of the first fixed plate. Multiple power telescopic components are connected to the middle of the central shaft. The other end of the central shaft passes through the third fixed plate and connects to the fourth fixed plate. The third fixed plate is provided with multiple locking holes, and the positions of the locking holes correspond to the power telescopic components. The rope drum is sleeved between the first fixed plate and the third fixed plate, and the power telescopic component is sleeved inside the rope drum.

[0024] A rotary motor driving the rope drum is located on the outer side of the first fixed plate, and a limiting rotation component is located at the central axis position on the inner side of the first fixed plate. The rotary motor assists in rotation; when the large reliquefaction equipment reaches its equilibrium point solely due to gravity, the rotary motor breaks the equilibrium, allowing the rope drum to continue rotating. The limiting rotation component controls the rotational speed of the rope drum, keeping it as slow as possible so that the elastic telescopic gear has sufficient time to extend into the locking hole of the third fixed plate.

[0025] Based on the above technical solutions, the hoisting method and dedicated hoisting equipment for large-scale reliquefaction equipment of the present invention have achieved the following technical advantages through practical application:

[0026] 1. The hoisting method and hoisting equipment of the present invention are required to solve the situation where it is not allowed to open large holes or multiple holes in the same compartment; and the situation where the opening is not above the base. They are labor-saving and time-saving, and at the same time, they are required to have a simple structure and be easy to operate and use.

[0027] 2. The hoisting method of the present invention, based on the construction schedule of the LNG ship, hoists the large reliquefaction equipment that is delivered later after the compartment has been installed. This ensures that the shipbuilding schedule is not affected by the late arrival of the large reliquefaction equipment. During the hoisting process, a dedicated hoisting hole is opened, and a special shifting hoisting device is designed inside the compartment. This allows for the smooth hoisting of the large reliquefaction equipment from the hoisting hole to the compartment. Furthermore, the crane can be used again in conjunction with the shifting hoisting device to complete a safe and stable positional movement, thereby completing the hoisting and installation work, greatly saving shipbuilding time and ensuring installation quality.

[0028] 3. The dedicated relocation and hoisting device of this invention fully utilizes the pulling force provided by the crane and hook, decomposing the pulling force into an upward lifting force and a horizontal pulling force for lateral displacement. First, the lifting ring is pulled upward by the hoisting rope to lift the large reliquefaction equipment off the floor. Then, the relocation rope is pulled by rotating the rope drum. The lower relocation rope pulls the large reliquefaction equipment horizontally. Because it is a loop rope, it can move around the hook and complete the relocation operation with the cooperation of the gantry bracket. Attached Figure Description

[0029] Figure 1 This is a flowchart illustrating the implementation of a method for hoisting large-scale reliquefaction equipment into the perforated compartment of an LNG ship according to the present invention.

[0030] Figure 2 This is a schematic diagram illustrating the hoisting of a large reliquefaction equipment into an open compartment of an LNG carrier, according to a method of the present invention.

[0031] Figure 3 This is a schematic diagram of the transfer rope connection after the equipment is hoisted into the compartment in a method for hoisting large reliquefaction equipment into the open compartment of an LNG ship according to the present invention.

[0032] Figure 4 This is a schematic diagram illustrating the initial tensioning of the upper displacement rope after the equipment is hoisted into the compartment of an LNG ship, as part of a method for hoisting a large reliquefaction equipment into the compartment of an LNG ship according to the present invention.

[0033] Figure 5 This is a schematic diagram showing the state of the rope reel after it has been hoisted into the compartment in a method for hoisting a large reliquefaction equipment into an open compartment of an LNG ship, according to the present invention.

[0034] Figure 6 This is a schematic diagram of the state during the lifting and shifting process towards the door support position in a method for lifting large reliquefaction equipment into the open compartment of an LNG ship according to the present invention.

[0035] Figure 7 This is a schematic diagram illustrating the state of the reliquefaction equipment being moved and lowered during the process of hoisting a large reliquefaction equipment into the open compartment of an LNG ship, according to the present invention.

[0036] Figure 8 This is a schematic diagram of the rope drum assembly in a relocation and hoisting device for hoisting large reliquefaction equipment into the open compartment of an LNG ship, according to the present invention.

[0037] Figure 9 This is a schematic diagram of the internal structure of the rope drum assembly in a relocation and hoisting device for hoisting large reliquefaction equipment into the open compartment of an LNG ship, according to the present invention.

[0038] Figure 10This is a bottom view structural diagram of the rope drum assembly in a relocation and hoisting device for hoisting large reliquefaction equipment into the open compartment of an LNG ship, according to the present invention.

[0039] In the diagram: 1—Compartment roof; 2—Crane hoisting rope; 3—Stabilizing rocker arm; 4—Shifting rope; 5—Large reliquefaction equipment; 6—Door support; 7—Rope drum assembly; 71—Left outrigger; 72—Second fixed plate; 73—Elastic telescopic gear; 74—Right outrigger; 75—First fixed plate; 76—Third fixed plate; 77—Rope drum; 78—Power telescopic component; 79—Fourth fixed plate; 70—Limiting rotation component; 701—Rotating motor; 8—Upper shifting rope. Detailed Implementation

[0040] The following detailed description, in conjunction with the accompanying drawings and specific embodiments, further elaborates on the process method and dedicated hoisting equipment for hoisting a large reliquefaction unit on a large LNG ship into an open compartment, in order to gain a clearer understanding of its structural composition and working method. However, this should not be construed as limiting the scope of protection of the present invention.

[0041] The process for hoisting large reliquefaction equipment into the open compartment of this invention is applied in the construction of large LNG carriers. Its purpose is to address the delays caused by the inability to transport large reliquefaction equipment to the dry dock for hoisting during the construction of large LNG carriers, which prevents simultaneous hoisting of the equipment. Waiting would extend the construction period and affect the entire process. Therefore, the approach of this invention is to adopt a method of building first and then hoisting, which does not affect the shipbuilding schedule and allows for subsequent hoisting.

[0042] like Figure 1 As shown, this invention provides a process for hoisting a large reliquefaction unit into an open compartment. The general flow includes: First, adjusting the ballast water to stabilize and balance the LNG carrier; second, creating a hoisting opening in the top of the compartment; third, installing a transfer hoisting device inside the compartment; fourth, using a crane to lift the large reliquefaction unit through the hoisting opening into the compartment, and then slack off the hoisting rope to switch to a transfer rope; fifth, raising the hoisting rope and using the transfer rope inside the compartment to lift the large reliquefaction unit off the ground; sixth, using the transfer hoisting device to move the large reliquefaction unit to the base for further installation; seventh, releasing the transfer rope, retracting the hook upwards, removing the stabilizing boom and the transfer hoisting device, closing the hoisting opening, and completing the hoisting of the large reliquefaction unit. The overall approach involves first creating an opening in the compartment, then hoisting the unit into the compartment, then transferring and installing it, and finally removing auxiliary equipment.

[0043] Specifically, the above steps can be broken down into the following steps:

[0044] The first step is to move the LNG carrier out of the dock after it has been built and launched to make way for the construction of other vessels. Ballast water is adjusted to keep the LNG carrier stable in the water so that it can be smoothly docked at the pier. The balance is also checked to prevent shaking during the hoisting process from affecting the installation.

[0045] The second step is to locate the compartment where the large reliquefaction equipment needs to be hoisted. This compartment is specifically designed to house the large reliquefaction equipment, which includes the reliquefaction control cabinet, the reliquefaction frequency converter control cabinet, and the reliquefaction system transformer. This equipment is quite heavy and cannot be lifted by ordinary cranes or hand-operated hoists; a shore-based crane is required. The compartment contains pre-installed equipment bases for the large reliquefaction equipment. The equipment needs to be placed on these bases and secured. To facilitate the subsequent hoisting of the equipment, a hoisting hole needs to be created in the compartment's roof (position 1). This hoisting hole is typically circular, with a diameter larger than the reliquefaction equipment's outline to allow it to be hoisted in. Therefore, the dedicated hoisting hole is generally located in the compartment's roof (position 1). Figure 2 As shown.

[0046] The third step is to install the transfer and hoisting equipment inside the cabin. This equipment includes a portal frame 6, a rope drum assembly 7, and a transfer rope 4. The portal frame 6 includes vertical rods on both sides and a top beam. The vertical rods are fixed to both sides of the equipment base, and the beam is located directly above the equipment base. The rope drum assembly 7 is installed on one side of the portal frame 6 away from the hoisting hole. The rope drum assembly 7 is equipped with outriggers, a rope drum, and an elastic telescopic gear. The two outriggers support the rope drum and the elastic telescopic gear respectively. According to the design connection, when the transfer rope 4 is wound around the rope drum, it needs to pass through the portal frame 6 from the bottom. Figure 2 and Figure 3 As shown.

[0047] The fourth step is to connect the hook on the crane to the lifting ring of the large reliquefaction equipment 5 using the crane rope 2. Four lifting rings are located at the four corners of the large reliquefaction equipment 5. For ease of connection and to ensure a sufficiently low center of gravity, the lifting rings are positioned at the top four corners of the large reliquefaction equipment 5, and a stable gripper is located in the middle of the large reliquefaction equipment 5. Four specific lifting ropes are connected to the hook and four lifting rings respectively, and each specific lifting rope is connected to a loop rope that loops the hook and the lifting ring. The connection between the loop rope and each lifting ring on the large reliquefaction equipment 5 is fixed in a non-rotating state. The crane is directed to lift the large reliquefaction equipment 5 and let it enter the cabin through the lifting hole at the top of the cabin. Then, a stabilizing rod 3 is fixed at the opening of the lifting hole in the cabin. The function of the stabilizing rod 3 is to control the position of the crane lifting rope 2 and ensure that it is supported to avoid back and forth swaying. Specifically, the stabilizing rod 3 is erected on the top 1 of the cabin across the lifting hole. The stabilizing rod 3 is located at the position of the maximum diameter of the circular opening. In order to improve the positional stability of the lifting rope 2 on the stabilizing rod 3, a limiting groove is provided in the middle of the stabilizing rod 3. The crane lifting rope 2 of the crane is movably set in the limiting groove. After the large reliquefaction equipment 5 is hoisted into the compartment and placed at the bottom, the crane lowers again until the hook is inside the compartment. At this time, the four specific lifting ropes connected to the four lifting rings are all in a slack state. The middle part of one side of the four specific lifting ropes is pulled towards the displacement lifting equipment, passes through the gantry bracket 6, and then wraps around the rope drum assembly 7. The lifting ropes pulling towards the displacement lifting equipment pass through the lower part of the gantry bracket. The specific lifting ropes wrapped on the rope drum are called displacement pull ropes. According to their position, they are divided into upper displacement pull ropes and lower displacement pull ropes. When the upper displacement pull rope 8 and the lower displacement pull rope are a single specific displacement lifting rope 4, the only distinction is that they are located at the top and bottom of the rope drum. The length of the specific lifting rope wrapped around the rope drum is one and a half turns of the circumference of the rope drum to ensure sufficient friction when the rope drum rotates. Multiple parallel loop ropes are installed on the lower displacement rope. These loop ropes are formed by bending and locking them onto the lower displacement rope using a locking buckle. By allocating the loop ropes to the lifting rings of the large reliquefaction equipment, the length and tension of the lower displacement rope are controlled. The key to this step is that a specific lifting rope located inside the compartment and connected to the displacement hoisting equipment becomes the displacement rope 4 that pulls the large reliquefaction equipment to a new position. Figure 3 As shown.

[0048] Fifth step, as Figure 4As shown, the crane initially lifts the lifting rope 2 upwards, so that the rope between the hook and the lifting ring acts as the upper shifting rope 8, making the upper shifting rope 8 taut and tilting towards the gantry 6. At this time, the upper shifting rope 8 is close to the top crossbeam of the gantry 6 and gradually becomes taut. The crane continues to pull upwards, at which point the hook will tilt towards the gantry and remain in a fixed position. The large liquefaction equipment 5 will move vertically below the crane hook. At this time, the lower shifting rope is in a slack state. The rope drum is started, and the length of each shifting rope is adjusted through the rope drum, converting the length of the lower shifting rope to the length of the upper shifting rope 8, so that both the upper and lower shifting ropes are in a taut state. At this time, the large liquefaction equipment descends a certain height, but the four lifting rings are still higher than the connection position between the lower shifting rope and the rope drum, and the hook is on one side of the gantry. Figure 5 As shown.

[0049] Step 6, as follows Figure 6 As shown, continue to slowly rotate the rope drum 77, and through the horizontal stretching of the lower displacement rope 4, slowly move the large reliquefaction equipment 5 horizontally towards the displacement hoisting equipment, specifically towards the gantry bracket 6. At this time, the large reliquefaction equipment will slowly fall. Once the large reliquefaction equipment has moved to the gantry bracket 6 and is directly above the equipment base, after the position is determined, release the hook on the crane downwards, and use the stabilizing grip on the large reliquefaction equipment 5 to control the falling position until the large reliquefaction equipment is located on the corresponding equipment base, the final state is as shown. Figure 7 As shown.

[0050] Step 7: Loosen the transfer rope 4 connected to the lifting ring of the large reliquefaction equipment. The crane will retract the hook upwards, remove the stabilizing rod 3, disassemble the transfer and lifting equipment and take it out of the compartment. Then, seal the lifting hole on the top of the compartment to complete the lifting of the large reliquefaction equipment.

[0051] like Figure 8 , Figure 9 and Figure 10As shown, the relocation and hoisting equipment includes a rope drum assembly 7. The rope drum assembly consists of outriggers, a first fixed plate 75, a second fixed plate 72, a third fixed plate 76, a fourth fixed plate 79, a rope drum 77, a power telescopic component 78, and elastic telescopic gears 73. The outriggers include a left outrigger 71 and a right outrigger 74. The left outrigger 71 is connected to the second fixed plate 72, and the right outrigger 74 is connected to the first fixed plate 75. A fixed shaft is connected to one side of the middle of the second fixed plate 72. Multiple elastic telescopic gears 73 are provided on the fixed shaft, and the fourth fixed plate 79 is fixed to the other end of the fixed shaft. One end of a central shaft is connected to one side of the middle of the first fixed plate 75. A plurality of the aforementioned power telescopic members 78 are connected to the middle of the central shaft. The other end of the central shaft passes through the third fixed plate 76 and is connected to the fourth fixed plate 79. The third fixed plate 76 is provided with a plurality of locking holes, the positions of which correspond to the aforementioned power telescopic members 78. The rope drum 77 is fitted between the first fixed plate 75 and the third fixed plate 76, and the power telescopic members 78 are fitted inside the rope drum 77.

[0052] The right outrigger 74 is first welded and fixed to the floor inside the cabin. After the displacement rope 3 is wound around the rope drum 77, the left outrigger 71 is then welded and fixed to the corresponding position of the right outrigger 74 inside the cabin, so that the elastic telescopic gear 73 aligns with the third fixed plate 76, allowing the elastic teeth on the elastic telescopic gear 73 to extend into the locking holes of the third fixed plate 76. Furthermore, there are four sets of elastic telescopic gears 73 fixed to the fixed shaft, arranged in pairs facing each other. Each set of elastic telescopic gears 73 has six elastic teeth. The elastic telescopic gears 73 do not rotate and are fixed. The four gears on the side limit the telescopic length to be exactly the thickness of the third fixed plate. The four gears of the four elastic telescopic gears 73 that contact the second fixed plate 72 are elastically telescopic. Simultaneously, the section of the fixed shaft connecting the elastic telescopic gears that contacts the second fixed plate 72 is also elastically telescopic.

[0053] Furthermore, a rotary motor 701 for driving the rope drum 77 to rotate is provided on the outer side of the first fixed plate 75, and a limiting rotation component 70 is provided at the central axis position on the inner side of the first fixed plate 75. The function of the rotary motor 701 is to assist rotation. When the reliquefaction large equipment 5 reaches the balance point by moving solely by gravity, the rotary motor 701 can break the balance and allow the rope drum 77 to continue rotating. The limiting rotation component 70 controls the rotational speed of the rope drum 77, making the rotational speed as slow as possible, so that the elastic telescopic gear 73 has sufficient time to extend into the locking hole of the third fixed plate 76.

[0054] Multiple adjustable buckles are installed on the looped ropes to control the length of the lower displacement ropes. These buckles serve a fixing function; controlling the length does not increase the overall length of the looped rope. However, by installing multiple buckles on four looped ropes and securing them to the same lifting ring, the length can be shortened, allowing for consistent initial lifting length for all four looped ropes. These buckles are located at the lifting ring of the large reliquefaction equipment. The buckles on the looped ropes serve two purposes: first, to prevent the looped ropes from swaying back and forth when lifting the lifting ring of the large reliquefaction equipment, thus improving stability; second, to ensure that when a portion of the lifting rope is converted into a displacement rope, it does not slip during rotation, thus ensuring effective displacement.

[0055] In step six above, when the remote-controlled rope drum is activated, the motor on the power telescopic component 78 drives the rotating rod to rotate, enabling the telescopic component to extend and retract. If the telescopic component extends and retracts to lock onto the third fixed plate 76, one of the elastic gears on the elastic telescopic gear 73 that is locked onto the third fixed plate 76 will retract. Since the shaft connecting the first fixed plate 75 to the rope drum 77 is rotatable, the rope drum 77, on which the crane and equipment wind the specific rope, will rotate. Afterwards, when the telescopic component on the power telescopic component 78 retracts, one of the elastic gears on the elastic telescopic gear 73 springs back and re-locks onto the third fixed plate 76. Because the second fixed plate 72, on which the elastic telescopic gear 73 is fixed, is stationary, it locks the rope drum 77, preventing it from rotating. This process repeats, controlling the equipment to slowly reach the final designated installation position. Since the elastic telescopic gear is fixed and does not rotate, the four gears on the side limit the extension length to be exactly the thickness of the third fixed plate. The four gears in contact with the second fixed plate are elastically extendable. At the same time, the section of the fixed shaft that connects to the elastic telescopic gear that contacts the second fixed plate is also elastically telescopic.

[0056] For rope drums, although geared segmented rotation is possible, an additional limiting rotation device can be added to control the rotation speed of the rope drum.

[0057] Furthermore, since the gantry bracket 6 bears most of the tension exerted on the ropes by the crane and equipment, it is necessary to control the height of the rope drum 77 and the gantry bracket 6 so that the force acting on the rope drum 77 after force analysis can be adapted to the operation of the rope drum 77. Afterwards, the rope drum 77 is shut down, and then, to facilitate landing, the crane is slowly lowered, while the ropes control the large equipment to ensure stability, allowing for successful landing and installation.

[0058] Of course, during implementation, depending on the size of the compartment and the outline of the large reliquefaction equipment to be hoisted, if multiple units need to be hoisted, a large opening can be made in the roof of the same compartment. The only difference is that the position of the hoisting equipment needs to be adjusted. Therefore, it is possible to hoist even if the corresponding opening is not above the base.

[0059] Undoubtedly, the above is merely a limited implementation of the method and lifting equipment for hoisting large reliquefaction equipment into the open compartment of an LNG carrier according to the present invention. Other feasible methods, steps, and structural alternatives are also possible. In summary, the scope of protection of the present invention also includes other variations and substitutions that are obvious to those skilled in the art.

Claims

1. A method for hoisting a large-scale reliquefaction unit into an open compartment of an LNG carrier, the large-scale reliquefaction unit comprising a reliquefaction control cabinet, a reliquefaction frequency converter control cabinet, and a reliquefaction system transformer, characterized in that, The method includes the following steps: The first step is to adjust the ballast water to stabilize the LNG carrier, so that it can be smoothly docked at the pier, and to check its balance. The second step is to locate the compartment where the large reliquefaction equipment needs to be hoisted. This compartment contains the equipment base for installing the large reliquefaction equipment, and hoisting holes are opened in the top of the compartment. The third step is to install the transfer and hoisting equipment inside the cabin. The hoisting equipment includes a door support, a rope drum assembly, and a transfer rope. The door support includes vertical rods on both sides and a top beam. The vertical rods are fixed to both sides of the equipment base, and the beam is located directly above the equipment base. The rope drum assembly is installed on one side of the door support away from the hoisting hole. The rope drum assembly is equipped with outriggers, a rope drum, and an elastic telescopic gear. The two outriggers support the rope drum and the elastic telescopic gear, respectively. The transfer rope is wound around the rope drum and passes through the door support. The fourth step involves connecting the crane hook to the lifting rings of the large reliquefaction equipment using lifting ropes. The equipment has four lifting rings at its four corners and a stabilizing grip in the center. Four lifting ropes are connected to the hooks and four lifting rings, with each rope forming a loop connecting the hook and the ring. The loop connection to the ring is fixed. The crane is then directed to lift the large reliquefaction equipment, entering the compartment through the lifting opening at the top. A stabilizing rod is then fixed at the opening of the lifting opening. Once the large reliquefaction equipment is lifted into the compartment... After the chamber is placed at the bottom, the hook on the crane continues to fall until the hook is inside the chamber. At this time, the four lifting ropes connected to the four lifting rings are all in a slack state. Pull the middle part of one side of the four lifting ropes toward the moving and lifting equipment, pass through the door bracket, and then wrap around the rope drum. Each loop rope is equipped with the lifting ring, rope drum and hook of the large reliquefaction equipment. The lifting rope connected to the moving and lifting equipment inside the chamber becomes the moving rope for moving the large reliquefaction equipment, and the moving rope near the bottom of the chamber is in a taut state. Fifth step: Instruct the crane to initially lift the hoisting rope, so that the hoisting rope between the hook and the lifting ring becomes the upper displacement rope, close to the top crossbeam of the gantry and gradually taut. Continue to pull the crane upward. At this time, the hook will tilt towards the gantry and remain in a fixed position. The large liquefaction equipment will move vertically below the crane hook. At this time, the lower displacement rope is in a slack state. Start the rope drum and adjust the length of each displacement rope through the rope drum to convert the length of the lower displacement rope to the length of the upper displacement rope, so that the upper and lower displacement ropes are both in a taut state. At this time, the large liquefaction equipment will descend a certain height, but the four lifting rings will still be higher than the connection position between the lower displacement rope and the rope drum, and the hook will be on one side of the gantry. Step 6: Slowly rotate the drum and stretch the lower displacement rope horizontally to slowly move the large reliquefaction equipment horizontally toward the gate support. At this time, the large reliquefaction equipment slowly falls. After the large reliquefaction equipment is moved to the gate support and is directly above the large equipment base, the position is determined. Then, release the hook on the crane downward and use the stabilizing grip on the large reliquefaction equipment to control the falling position until the large reliquefaction equipment is placed on the corresponding equipment base. Step 7: Loosen the transfer rope connected to the lifting ring of the large reliquefaction equipment. The crane will retract the hook upwards, remove the stabilizing rod, disassemble the transfer and lifting equipment and take it out of the compartment. Then, seal the lifting hole on the top of the compartment to complete the lifting of the large reliquefaction equipment.

2. The method for hoisting multiple large reliquefaction units into the perforated compartment of an LNG carrier according to claim 1, characterized in that, In the third step, the relocation and hoisting equipment includes a rope drum assembly. This assembly comprises outriggers, a first fixed plate, a second fixed plate, a third fixed plate, a fourth fixed plate, a rope drum, a power telescopic component, and elastic telescopic gears. The outriggers include a left outrigger and a right outrigger. The left outrigger connects to the second fixed plate, and the right outrigger connects to the first fixed plate. A fixed shaft is connected to one side of the middle of the second fixed plate, and multiple elastic telescopic gears are mounted on this shaft. The other end of the fixed shaft is fixed to the fourth fixed plate. A central shaft is connected to one side of the middle of the first fixed plate, and multiple power telescopic components are connected to the middle of this central shaft. The other end of the central shaft passes through the third fixed plate and connects to the fourth fixed plate. The third fixed plate has multiple locking holes, the positions of which correspond to the power telescopic components. The rope drum is fitted between the first and third fixed plates, and the power telescopic component is fitted inside the rope drum. A rotating motor is located outside the first fixed plate, and a limiting rotation component is located at the central shaft position inside the first fixed plate.

3. The method for hoisting multiple large reliquefaction devices into the perforated compartment of an LNG carrier according to claim 2, characterized in that, The right outrigger is first welded and fixed to the floor inside the cabin. After the displacement rope is wound around the rope drum, the left outrigger is then welded and fixed to the position opposite to the right outrigger inside the cabin, so that the elastic telescopic gear is engaged with the third fixed plate, and the elastic teeth on the elastic telescopic gear extend into the locking holes of the third fixed plate.

4. The method for hoisting multiple large reliquefaction units into the perforated compartment of an LNG carrier according to claim 3, characterized in that, There are four sets of elastic telescopic gears fixed on the fixed shaft. The four sets of elastic telescopic gears are arranged in pairs facing each other. The four gears on the upper side of the elastic telescopic gear limit the telescopic length to the thickness of the third fixed plate. The four gears on the four sets of elastic telescopic gears that are in contact with the second fixed plate are elastically telescopic. The fixed shaft connecting the elastic telescopic gears is also elastically telescopic at the end that is in contact with the second fixed plate.

5. The method for hoisting multiple large reliquefaction devices into the perforated compartment of an LNG carrier according to claim 1, characterized in that, In the fourth step, the stabilizer bar is installed in the hoisting hole of the cabin. The stabilizer bar is located at the position of the maximum diameter of the circular opening. A limiting groove is provided in the middle of the stabilizer bar, and the hoisting rope of the crane is movably installed in the limiting groove.

6. The method for hoisting multiple large reliquefaction units into the perforated compartment of an LNG carrier according to claim 1, characterized in that, In the fourth step, the lifting rings are positioned at the four corners of the large reliquefaction equipment near the top.

7. The method for hoisting multiple large reliquefaction units into the perforated compartment of an LNG carrier according to claim 1, characterized in that, In the fourth step, multiple buckles are provided on the loop-shaped rope, and the length of the loop-shaped rope can be selected by choosing one set of the multiple buckles on the lifting ring.

8. The method for hoisting multiple large reliquefaction units into the perforated compartment of an LNG carrier according to claim 1, characterized in that, In the fourth step, the hoisting rope for the moving and lifting equipment passes through the lower part of the gantry bracket and is close to the top crossbeam.

9. A method for hoisting multiple large reliquefaction units into the perforated compartment of an LNG carrier according to claim 1, characterized in that, In the fourth step, the displacement rope, which is looped on the rope drum, is wound for one and a half turns of the circumference of the rope drum.

10. A moving and lifting device for hoisting large-scale reliquefaction equipment, characterized in that, Its structure includes a door support, a rope drum assembly, and a displacement rope. The door support includes vertical bars on both sides and a top beam. The vertical bars are fixed to both sides of the equipment base, and the beam is located directly above the equipment base. The rope drum assembly is installed on one side of the door support away from the lifting hole. The rope drum assembly is equipped with support legs, a rope drum, and an elastic telescopic gear. The two support legs support the rope drum and the elastic telescopic gear respectively. The displacement rope is wound around the rope drum and passes through the door support. The rope drum assembly further includes support legs, a first fixed plate, a second fixed plate, a third fixed plate, a fourth fixed plate, and a power telescopic component. The support legs include a left support leg and a right support leg. The left support leg is connected to the second fixed plate, and the right support leg is connected to the first fixed plate. A fixed shaft is connected to one side of the middle of the second fixed plate. The fixed shaft is provided with multiple elastic telescopic gears, and the fourth fixed plate is fixed to the other end of the fixed shaft. One end of a central shaft is connected to one side of the middle of the first fixed plate. Multiple power telescopic components are connected to the middle of the central shaft. The other end of the central shaft passes through the third fixed plate and connects to the fourth fixed plate. The third fixed plate is provided with multiple locking holes, and the positions of the locking holes correspond to the power telescopic components. The rope drum is sleeved between the first fixed plate and the third fixed plate, and the power telescopic component is sleeved inside the rope drum. A rotating motor is provided on the outside of the first fixed plate, and a limiting rotating component is provided on the inner central axis of the first fixed plate.

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