Motor dismantling and cabin entering and exiting process for LNG ship generator set

Abstract

The invention relates to the technical field of ship construction, in particular to an LNG ship generator set motor dismantling and cabin entering and exiting technology. The method comprises the following steps: S1, preparation before delivery from a cabin: sequentially arranging a fourth platform, a third platform, a second platform and an upper deck on an LNG ship from bottom to top, mounting a plurality of generator sets on the fourth platform, dismounting cooling water tanks of the generator sets, and forming a hoisting-out channel from bottom to top by forming temporary holes; s2, taking out of a cabin, wherein a motor rotor part is hoisted to an upper deck through a hoisting eye plate on the LNG ship, and then is hoisted out for maintenance through shore falling; and S3, cabin entering: maintaining or replacing a motor rotor part, enabling the motor rotor part to sequentially pass through a hoisting area III of the upper deck, a hoisting area II of the second platform and a hoisting area I of the third platform along the hoisting-out channel, assembling the motor rotor part and the cooling water tank, and assembling the disassembled pipeline. The lifting device is used for solving the problem that in the prior art, a generator set cannot be directly lifted and replaced.

Description

Technical Field

[0001] The present invention relates to the technical field of shipbuilding, and in particular to a process for dismantling a motor of an LNG ship generator set and entering and exiting a cabin. Background Art

[0002] The diesel generator sets of large LNG ships are huge, 8-12 meters long, 2.8-3.2 meters wide, 3.8-4.2 meters high, and weigh 60-80 tons. When they are first installed on a new ship, they need to be hoisted in and installed with the help of a crane due to their size and weight. However, when the unit is damaged and needs repair, there are cabins or other hull structures above the generator set, and they cannot be directly lifted out by a crane. This has become a technical problem that needs to be solved urgently. Previously, those skilled in the art have made efforts, such as the component maintenance and transfer system and transfer method for container ship cargo holds with Chinese patent publication number CN116118933A, which realizes the quadruple functions of component disassembly and lifting through reasonable layout. However, this solution still has shortcomings. The mature layout of the hull and the complex piping system cannot be used as a reference, making it impossible to remove the cabin or other hull structures above the generator set for lifting. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the shortcomings of the existing technology and provide a LNG ship generator set motor removal and entry and exit process to solve the problem that the generator set cannot be directly lifted and replaced in the existing technology.

[0004] The technical solution adopted in the present invention is as follows: A process for removing the motor of an LNG ship generator set and entering and exiting the cabin includes the following steps: S1. Preparation before leaving the cabin: The LNG ship is equipped with the fourth platform, third platform, second platform and upper deck from bottom to top. Several generator sets are installed on the fourth platform. The cooling water tanks of the generator sets are removed and a temporary opening is made to form a lifting channel from bottom to top, including the following steps: S11. Make temporary openings on the second platform and upper deck to form hoisting channels; S12, dismantling the pipeline below the temporary opening on the second platform; S13. Remove the cooling water tank on the generator set on the fourth platform; S14. Prepare the ropes and hoists used to pull and lift the generator set; S2. Exit: The motor rotor is lifted to the upper deck through the lifting eye plate on the LNG carrier, and then lifted out from the shore for maintenance, including the following steps: S21, lift the motor rotor part to the lifting area I of the third platform; S22, hoist the motor rotor part along the temporary opening along the hoisting channel to the hoisting area II of the second platform; S23. Hoist from hoisting area III on the upper deck to the upper deck; S3. Entering the cabin: Repair or replace the motor rotor part, follow the hoisting channel through the hoisting area III on the upper deck, the hoisting area II on the second platform, and the hoisting area I on the third platform, and assemble the motor rotor part with the cooling water tank and the dismantled pipelines.

[0005] This technical solution utilizes strategically located temporary openings within an already constructed LNG vessel, combined with pre-installed lifting eyeplates, to lift the typically large and heavy generator sets, enabling removal and access with minimal compromise. Specifically, pre-exit preparations are first performed by creating temporary openings on the second platform and upper deck to remove obstructing pipes and cooling water tanks. This creates a continuous lifting channel from bottom to top, transforming the previously enclosed space into a maneuverable linear path. During exit, the motor rotor is transferred in stages using the vessel's built-in lifting eyeplates and shore cranes. The lifting areas on the third and second platforms serve as transfer points, ensuring a smooth transition of heavy loads and avoiding the risks associated with excessive single lift heights. Upon entry, the reverse process is performed, utilizing the established channel and lifting area to reposition the repaired or replaced motor rotor, reassemble the cooling water tanks and piping, and restore system integrity. Through space optimization, phased lifting, and modular assembly, this entire process addresses the technical challenges of replacing LNG vessel generator sets in a cost-effective and efficient manner.

[0006] In addition, the above-mentioned LNG ship generator set motor removal and cabin entry and exit process according to the present invention may also have the following additional technical features: According to one embodiment of the present invention, in step S1, lifting eye plates I are installed on the left and right sides and front and back of the upper edge of the generator set on the fourth platform, and lifting ears for matching ropes and hoists are provided on the lifting eye plates I.

[0007] In this technical solution, ropes and hoists are commonly used lifting components, which can be quickly and reliably fixed to the lifting eye plate I through the lifting lugs, avoiding slippage or overloading problems caused by improper connection methods; the lifting eye plate I has been welded to the hull structure, not temporarily; the distributed installation of the lifting eye plate I can disperse the lifting load.

[0008] According to one embodiment of the present invention, in step S12, the pipeline below the temporary opening is provided with: Left condensate main pipe I, used to connect the left condensate pipe of the fourth platform; Left condensate main pipe II, used to connect the left condensate pipe on the bottom floor; Air main I, used to connect the control air pipe of the fourth platform; The main flushing pipe is used to connect the flushing pipe of the seabed door; Port main pipe I, used to connect to the port pipe of the fourth platform; Port main pipe II, used to connect the port pipe on the bottom layer; Port main pipe III, used to connect the port pipe of the third platform; Left condensate main pipe III, used to connect the left condensate pipe of the third platform; The quick closing valve control air pipe is used to connect the quick closing valve control air pipe of the generator of the fourth platform.

[0009] In this technical solution, there are certain rules for selecting temporary openings on LNG ships. First, from a functional zoning perspective, areas with concentrated main pipe layouts are selected, as main pipes have fewer branches than branch pipes. For example, the condensate main pipe is responsible for condensate transmission, the air main pipe ensures and controls air supply, the purge main pipe is used for cleaning the seabed doors, the port main pipe connects to relevant port pipelines, and the quick-closing valve control air pipe serves the generator quick-closing valve. Second, from a hierarchical interconnection perspective, each main pipe not only connects to the pipelines on its own level but also extends to the bottom layer and the third platform, forming a three-dimensional pipeline network. Temporary openings are selected in areas with larger pipeline adjustment space to avoid affecting the overall system due to changes to a single level of pipelines.

[0010] According to one embodiment of the present invention, in step S22, a turning channel is provided between the hoisting area II of the third platform and the temporary opening, and the turning channel is located on a side close to the air duct I and the escape port I.

[0011] In this technical solution, air duct I provides ventilation guarantee to reduce the risk of fire or explosion caused by sparks generated by equipment friction, collision, etc. during lifting; escape port I provides a rapid evacuation channel for emergency situations. Once an accident occurs, the operator can quickly escape from the dangerous area through escape port I to reduce casualties.

[0012] According to one embodiment of the present invention, in step S22, a lifting eye plate II is provided between the lifting area II of the third platform and the temporary opening, and a lifting lug for cooperating with a rope and a hoist is provided on the lifting eye plate II.

[0013] In this technical solution, the principles and functions of the lifting eye plate II are similar to those of the lifting eye plate I, and will not be repeated here.

[0014] According to one embodiment of the present invention, in step S23, the hoisting area III of the upper deck is located on a side close to the air duct II and the escape port II.

[0015] In this technical solution, the installation position of lifting area III is similar to that of lifting area II, and will not be repeated here.

[0016] According to one embodiment of the present invention, in step S1, the generator set is located at rib position 26 to rib position 30 of the LNG ship, weighs 60-80 tons, is 8-12 meters long, 2.8-3.2 meters wide, and 3.8-4.2 meters high.

[0017] In this technical solution, since the generator set is very large in size and weight, when the generator set is initially installed on a new ship, the generator set is hoisted into place by a crane for installation.

[0018] According to one embodiment of the present invention, in step S1, the temporary opening is 4-6 meters long and 2.8-3.5 meters wide.

[0019] In this technical solution, the size of the temporary opening meets the requirements for lifting out the motor rotor part.

[0020] According to one embodiment of the present invention, in step S1 , the motor rotor portion is vertically lifted upward from the temporary opening.

[0021] In this technical solution, the generator set lies horizontally on the fourth platform. When lifting, vertical lifting is selected to reduce the size of the temporary opening.

[0022] Compared with the prior art, the present invention has the following beneficial effects: (1) Safe and efficient lifting: The motor rotor is transferred in stages using the ship's own lifting eye plates and shore cranes. The lifting areas of each platform are used as transfer nodes to achieve a smooth transition of heavy objects and avoid the risk of excessive height in a single lift. At the same time, the lifting eye plates are installed in a distributed manner to disperse the lifting load, and the ropes and hoists are quickly and reliably fixed through the lifting lugs to avoid slippage or overloading problems, ensuring safe and efficient lifting. (2) Optimizing space utilization: Rationally plan the location of temporary openings, construct continuous lifting channels, and transform closed spaces into operable paths; select areas with larger pipeline adjustment spaces for temporary openings to reduce the impact on the overall system; lift the motor rotor vertically to reduce the size of temporary openings and make full use of the limited space on the ship. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is an overall process diagram of the present invention.

[0024] Figure 2 This is the process drawing of the third platform and the fourth platform.

[0025] Figure 3 This is the process drawing of the second platform and the third platform.

[0026] Figure 4 is a cross-sectional view of the temporary opening of the second platform.

[0027] Figure 5 This is the process drawing of the upper deck and the second platform.

[0028] In the figure: 1. Fourth platform; 11. Lifting eye plate I; 2. Third platform; 21. Hoisting area I; 3. Second platform; 31. Temporary opening; 311. Left condensate main pipe I; 312. Left condensate main pipe II; 313. Air main pipe I; 314. Purge main pipe; 315. Port main pipe I; 316. Port main pipe II; 317. Port main pipe III; 318. Left condensate main pipe III; 319. Air pipe controlled by quick-closing valve; 32. Hoisting area II; 33. Air duct I; 34. Escape port I; 35. Lifting eye plate II; 4. Upper deck; 41. Hoisting area III; 42. Air duct II; 43. Escape port II; 5. Generator set; 6. Motor rotor part; 7. Hoisting passage. DETAILED DESCRIPTION

[0029] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0030] Example 1 like Figures 1 to 5 As shown, this embodiment provides a process for removing the motor of an LNG ship generator set and entering and exiting the cabin, including the following steps: S1. Preparation before leaving the ship: The LNG ship is provided with a fourth platform 1, a third platform 2, a second platform 3 and an upper deck 4 from bottom to top. Several generator sets 5 are installed on the fourth platform 1. The cooling water tanks of the generator sets 5 are removed and a temporary opening 31 is opened to form a lifting channel 7 from bottom to top. The steps include the following: S11, temporary openings 31 are respectively opened on the second platform 3 and the upper deck 4 to form a lifting channel 7; S12, removing the pipeline below the temporary opening 31 of the second platform 3; S13, removing the cooling water tank on the generator set 5 of the fourth platform 1; S14, prepare the rope and hoist used to pull and lift the generator set 5; S2. Exit: The motor rotor part 6 is lifted to the upper deck 4 through the lifting eye plate on the LNG ship, and then lifted out by shore for maintenance, including the following steps: S21, lifting the motor rotor part 6 to the lifting area I21 of the third platform 2; S22, hoisting the motor rotor part 6 along the hoisting channel 7 and along the temporary opening 31 to the hoisting area II 32 of the second platform 3; S23, hoisting from hoisting area III 41 of upper deck 4 to upper deck 4; S3. Entering the cabin: Repair or replace the motor rotor part 6, and pass through the lifting area III 41 of the upper deck 4, the lifting area II 32 of the second platform 3, and the lifting area I 21 of the third platform 2 along the lifting channel 7 in sequence, and assemble the motor rotor part 6 with the cooling water tank and assemble the removed pipelines.

[0031] like Figures 1 to 5 As shown, this technical solution rationally arranges the location of temporary openings 31 on an already constructed LNG vessel, utilizing pre-installed lifting eyeplates to lift the originally large and heavy generator set 5, enabling removal and access with minimal compromise. Specifically, pre-exit preparations are first performed: temporary openings 31 are created on the second platform 3 and upper deck 4, obstructing pipes and cooling water tanks are removed, and a continuous lifting passage 7 is constructed from bottom to top, transforming the previously enclosed space into a maneuverable linear path. During exit, the motor rotor is transferred in stages using the vessel's built-in lifting eyeplates and shore cranes. The lifting areas of the third platform 2 and second platform 3 serve as transfer nodes, ensuring a smooth transition of heavy objects and avoiding the risks associated with excessive single lift heights. Upon entry, the reverse process is performed, utilizing the established passage and lifting area to reposition the repaired or replaced motor rotor, reassemble the cooling water tank and piping, and restore system integrity. Through space optimization, phased lifting, and modular assembly, the entire process addresses the technical challenges of replacing the LNG vessel's generator set 5 in a cost-effective and efficient manner.

[0032] In addition, the above-mentioned LNG ship generator set motor removal and cabin entry and exit process according to the present invention may also have the following additional technical features: According to one embodiment of the present invention, in step S1, lifting eye plates I11 are installed on the fourth platform 1 on the left and right sides and front and back of the generator set 5, and the lifting eye plates I11 are provided with lifting ears for matching ropes and hoists.

[0033] In this technical solution, ropes and hoists are commonly used lifting components, which can be quickly and reliably fixed to the lifting eye plates I11 through lifting ears, avoiding slippage or overloading problems caused by improper connection methods; the lifting eye plates I11 have been welded to the hull structure, and are not temporary welding; the distributed installation of the lifting eye plates I11 can disperse the lifting load.

[0034] According to one embodiment of the present invention, in step S12, the pipeline below the temporary opening 31 is sequentially provided with: The left condensate main pipe I 311 is used to connect to the left condensate pipe of the fourth platform 1; Left condensate main pipe II 312, used to connect to the left condensate pipe on the bottom floor; Air main pipe I 313, used for connecting the control air pipe of the fourth platform 1; A purge main pipe 314 is used to connect the purge pipe of the submarine door; Port main pipe I 315, used to connect to the port pipe of the fourth platform 1; Port main pipe II 316, used to connect the port pipe on the bottom layer; Port main pipe III 317, used to connect the port pipe of the third platform 2; The left condensate main pipe III 318 is used to connect to the left condensate pipe of the third platform 2; The quick-closing valve control air pipe 319 is used to connect the quick-closing valve control air pipe 319 of the generator of the fourth platform 1.

[0035] In this technical solution, the selection of temporary openings 31 for LNG ships follows certain rules. First, from a functional zoning perspective, areas with concentrated main pipe layouts are selected, as these are fewer than branch pipes. For example, the condensate main pipe is responsible for condensate transmission, the air main pipe ensures and controls air supply, the purge main pipe 314 is used for subsea door cleaning, the port main pipe connects to relevant port piping, and the quick-closing valve control air pipe 319 specifically serves the generator quick-closing valve. Second, from a hierarchical interconnection perspective, each main pipe not only connects to the pipelines on its own level but also extends to the bottom layer and the third platform 2, forming a three-dimensional pipeline network. Temporary openings 31 are selected in areas with ample room for pipeline adjustment to avoid impacting the overall system due to changes to a single level of piping.

[0036] According to one embodiment of the present invention, in step S22 , a turning channel is provided between the hoisting area II 32 of the third platform 2 and the temporary opening 31 , and the turning channel is located on a side close to the air duct I 33 and the escape port I 34 .

[0037] In this technical solution, air duct I 33 provides ventilation guarantee, reducing the risk of fire or explosion caused by sparks generated by equipment friction, collision, etc. during lifting; escape port I 34 provides a rapid evacuation channel for emergency situations. Once an accident occurs, the operator can quickly escape from the dangerous area through escape port I 34, reducing casualties.

[0038] According to one embodiment of the present invention, in step S22, a lifting eye plate II 35 is provided between the lifting area II 32 of the third platform 2 and the temporary opening 31, and a lifting lug for cooperating with a rope and a hoist is provided on the lifting eye plate II 35.

[0039] In this technical solution, the principles and functions of the lifting eye plate II 35 are similar to those of the lifting eye plate I 11 and will not be described in detail here.

[0040] According to one embodiment of the present invention, in step S23 , the hoisting area III 41 of the upper deck 4 is located on a side close to the air duct II 42 and the escape port II 43 .

[0041] In this technical solution, the installation position of the lifting area III 41 is similar to that of the lifting area II 32 and will not be described in detail here.

[0042] According to one embodiment of the present invention, in step S1, the generator set 5 is located at rib position 26 to rib position 30 of the LNG ship, weighs 60-80 tons, is 8-12 meters long, 2.8-3.2 meters wide, and 3.8-4.2 meters high.

[0043] In this technical solution, since the generator set 5 is very large in size and weight, when the generator set 5 is initially installed on a new ship, the generator set 5 is hoisted into the ship by a crane for installation.

[0044] According to one embodiment of the present invention, in step S1, the temporary opening 31 is 4-6 meters long and 2.8-3.5 meters wide.

[0045] In this technical solution, the size of the temporary opening 31 meets the requirements for lifting out the motor rotor part 6.

[0046] According to one embodiment of the present invention, in step S1 , the motor rotor part 6 is lifted vertically upward from the temporary opening 31 .

[0047] In this technical solution, the generator set 5 lies horizontally on the fourth platform 1 , and when hoisting, vertical hoisting is selected in order to reduce the size of the temporary opening 31 .

[0048] like Figures 1 to 5 As shown, the present invention utilizes the ship's own lifting eye plates and shore cranes to transfer the motor rotor in stages, and uses the lifting areas of each platform as transfer nodes to achieve a smooth transition, avoiding the risk of excessive single lifting height. At the same time, a distributed installation of lifting eye plates is used to disperse the load, and lifting ears are used to quickly and reliably fix ropes and hoists to prevent slippage and unbalanced loading, ultimately achieving the purpose of safely and efficiently lifting the motor rotor; it constructs a continuous lifting channel 7 by rationally planning the position of temporary openings 31, turning the closed space into an operable path, selecting openings in larger areas of pipeline adjustment space to reduce the impact on the overall system, and adopting a vertical lifting method for the motor rotor to reduce the size of the temporary opening 31, ultimately achieving the purpose of making full use of the limited space of the ship.

[0049] Although the present invention has been described in detail with reference to the accompanying drawings and in conjunction with preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and essence of the present invention, a person of ordinary skill in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and such modifications or substitutions shall be within the scope of the present invention. Any person skilled in the art who can easily conceive of changes or substitutions within the technical scope disclosed in the present invention shall be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be based on the scope of protection of the claims.

Claims

1. A process for dismantling the motor of an LNG ship generator set and entering and exiting the cabin, characterized in that: The steps include: S1. Preparation before leaving the cabin: The LNG ship is provided with a fourth platform (1), a third platform (2), a second platform (3) and an upper deck (4) in order from bottom to top. Several generator sets (5) are installed on the fourth platform (1). The cooling water tanks of the generator sets (5) are removed and a lifting channel (7) is formed from bottom to top by opening a temporary opening (31). The steps include the following: S11, opening temporary openings (31) on the second platform (3) and the upper deck (4) respectively to form a lifting channel (7); S12, dismantling the pipeline below the temporary opening (31) of the second platform (3); S13, dismantling the cooling water tank on the generator set (5) on the fourth platform (1); S14, prepare the rope and hoist used to pull and lift the generator set (5); S2. Exit: The motor rotor part (6) is lifted to the upper deck (4) through the lifting eye plate on the LNG ship, and then lifted out from the shore for maintenance, including the following steps: S21, lifting the motor rotor part (6) to the lifting area I (21) of the third platform (2); S22, hoisting the motor rotor part (6) along the hoisting channel (7) and along the temporary opening (31), and hoisting it to the hoisting area II (32) of the second platform (3); S23, hoisting from hoisting area III (41) of the upper deck (4) to the upper deck (4); S3. Entering the cabin: Repair or replace the motor rotor part (6), and pass through the lifting area III (41) of the upper deck (4), the lifting area II (32) of the second platform (3), and the lifting area I (21) of the third platform (2) along the lifting channel (7), and assemble the motor rotor part (6) with the cooling water tank and assemble the removed pipelines.

2. The LNG ship generator set motor removal and cabin entry and exit process according to claim 1 is characterized in that: In the step S1, a lifting eye plate I (11) is installed on the fourth platform (1) on the left and right sides and the front and back sides of the generator set (5), and the lifting eye plate I (11) is provided with a lifting lug for matching the rope and the hoist.

3. The LNG ship generator set motor removal and cabin entry and exit process according to claim 1 or 2, characterized in that: In step S12, the pipeline below the temporary opening (31) is provided with: The left condensate main pipe I (311) is used to connect the left condensate pipe of the fourth platform (1); The left condensate main pipe II (312) is used to connect the left condensate pipe on the bottom floor; Air main pipe I (313), used for connecting to the control air pipe of the fourth platform (1); A main purge pipe (314) for connecting to a purge pipe of a submarine gate; The port main pipe I (315) is used to connect the port pipe of the fourth platform (1); Port main pipe II (316), used to connect the port pipe on the bottom layer; The port main pipe III (317) is used to connect the port pipe of the third platform (2); The left condensate main pipe III (318) is used to connect the left condensate pipe of the third platform (2); The quick closing valve control air pipe (319) is used to connect the quick closing valve control air pipe (319) of the generator of the fourth platform (1).

4. The LNG ship generator set motor removal and cabin entry and exit process according to claim 1 is characterized in that: In step S22, a turning channel is provided between the hoisting area II (32) of the third platform (2) and the temporary opening (31), and the turning channel is located on a side close to the air duct I (33) and the escape port I (34).

5. The LNG ship generator set motor removal and cabin entry and exit process according to claim 1 or 4, characterized in that: In the step S22, a lifting eye plate II (35) is provided between the lifting area II (32) of the third platform (2) and the temporary opening (31), and a lifting lug for matching the rope and the hoist is provided on the lifting eye plate II (35).

6. The LNG ship generator set motor removal and cabin entry and exit process according to claim 5 is characterized in that: In step S23, the hoisting area III (41) of the upper deck (4) is located on a side close to the air duct II (42) and the escape port II (43).

7. The LNG ship generator set motor removal and cabin entry and exit process according to claim 1 is characterized in that: In step S1, the generator set (5) is located at rib position 26 to rib position 30 of the LNG ship, weighs 60-80 tons, is 8-12 meters long, 2.8-3.2 meters wide, and 3.8-4.2 meters high.

8. The LNG ship generator set motor removal and cabin entry and exit process according to claim 7 is characterized in that: In step S1, the temporary opening (31) is 4-6 meters long and 2.8-3.5 meters wide.

9. The LNG ship generator set motor removal and cabin entry and exit process according to claim 8 is characterized in that: In step S1, the motor rotor part (6) is lifted vertically upward from the temporary opening (31).

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