Self-adaptive fender system suitable for LNG (Liquefied Natural Gas) side-by-side conveying

Abstract

A self-adaptive fender system suitable for LNG side-by-side conveying is applied to an FSRU or FLNG or other fixed offshore LNG treatment platforms, movable fenders are fixed to the bow end and the stern end of a parallel midbody deck of a floating LNG receiving treatment platform respectively, and fixed fenders are fixed to the two ends of a collecting pipe area of the floating LNG receiving treatment platform respectively. The sound wave range finder is fixed to the end close to the bow portion of the fender body located on the bow portion of the parallel midbody deck, and the sound wave range finder is fixed to the end close to the stern portion of the fender body located on the stern portion of the parallel midbody deck. And the actual distance between the floating LNG receiving and processing platform and the LNG ship is continuously measured, the actual distance is compared with the theoretical distance, the movable fender moves till the actual distance is equal to the theoretical distance, and then the fender system automatically adapts to the parallel midbody range of the LNG ship. All the fender devices are always located in the parallel middle bodies of the two ships, and the situation that due to the fact that the positions of traditional fender devices cannot be adjusted, the traditional fender devices are located outside the parallel middle bodies of the LNG ships, and fenders fail is avoided.

Description

Technical Field

[0001] The invention belongs to the field of construction and design of shipping LNG storage tanks, and in particular relates to an adaptive fender system suitable for LNG siding transportation. Background Art

[0002] With the increasing global demand for clean energy, especially the growing demand for LNG, not only has the global demand for LNG shipping increased sharply, but it has also caused a surge in natural gas prices in the global energy market.

[0003] Currently, floating LNG receiving and processing platforms (FSRU, FLNG, etc.) are favored by more and more countries and regions due to their advantages such as short construction period, low investment and good environmental protection.

[0004] When LNG is transferred between the floating LNG receiving and processing platform and the LNG ship, the side-by-side external transmission method is adopted, that is, one side of the LNG ship is moored on one side of the floating LNG receiving and processing platform, the two are connected by cables, and fenders are installed to avoid direct collision between the two.

[0005] The fender device is installed on the floating LNG receiving and processing platform. A fender is set at each end of the parallel mid-body, and a fender is set before and after the manifold. [1] .

[0006] [1] China Classification Society, Guidelines for Ship-to-Ship Transfer. [S], CCS.2019.

[0007] At present, fenders are all fixedly installed. The positions of the fenders on both sides of the parallel mid-body are determined based on the parallel mid-body range of the floating LNG receiving and processing platform.

[0008] However, the sizes and specifications of LNG ships vary greatly, resulting in large differences in the length of their parallel mid-body. When the parallel mid-body of an LNG ship is smaller than the parallel mid-body of a floating LNG receiving and processing platform, the fenders at both ends of the parallel mid-body of the floating LNG receiving and processing platform will not be able to contact the hull plate of the LNG ship, resulting in partial or complete suspension, which in turn causes the fenders at that location to lose their collision avoidance function, increasing the risk of LNG siding external transmission. Summary of the invention

[0009] In order to solve the above problems, the present invention proposes an adaptive fender system suitable for LNG siding transportation, and the technical solution adopted is:

[0010] The invention discloses an adaptive fender system suitable for LNG siding transportation. A movable fender is fixed at both ends of the bow and stern of the parallel mid-body deck of a floating LNG receiving and processing platform, and a fixed fender is fixed at both ends of the manifold area of ​​the floating LNG receiving and processing platform.

[0011] The movable fender includes a track, an automatic cable winch and a fender body. The track is fixed on the deck. The track includes a track support frame and a rack. Limiting members are set at both ends of the track support frame, and the rack is located in the middle of the track support frame. The track is slidably connected with an automatic cable winch. The automatic cable winch includes a winch frame. A gear is fixed at the bottom center of the winch frame. The gear meshes with the rack teeth. Drums are fixed at both ends of the winch frame. The two drums are coaxially connected. The automatic cable winch is equipped with a gear box. The gear box is connected to the two drum shafts. The gear box is controlled by a first motor. A cable is wound on the drum. The cable is fixedly connected to the end of the fender body. The angle between the cable and the axis of the fender body is 45°≤β≤60°. The end of the fender body of the movable fender is also provided with an acoustic rangefinder. For the fender body located parallel to the bow of the mid-body deck, the acoustic rangefinder is fixed at one end near the bow, and for the fender body located parallel to the stern of the mid-body deck, the acoustic rangefinder is fixed at one end near the stern. The length of the fender body is selected according to the diameter of the fender body and in accordance with ISO 17357:2002 standard.

[0012] The fixed fender consists of a fender body and a cable holder. The cable holder is fixed on the deck. Cables are connected to both ends of the fender body, and the other end of the cable is connected to the cable holder. The angle between the cable and the axis of the fender body is 45°≤β≤60°.

[0013] The above-mentioned adaptive fender system suitable for LNG siding transportation, further, the gear is driven by a second motor.

[0014] The above-mentioned adaptive fender system suitable for LNG siding transportation, further, the fender body is an inflatable fender.

[0015] The above-mentioned adaptive fender system suitable for LNG siding transportation further comprises eye plates fixed at both ends of the fender body, and the cables are connected to the eye plates.

[0016] The above-mentioned adaptive fender system suitable for LNG siding transportation, further, the winch frame is a steel winch frame.

[0017] The above-mentioned adaptive fender system suitable for LNG siding transportation further has a cable guide hole arranged at the front end of the drum, and the cable passes through the cable guide hole and is connected to the end of the fender body.

[0018] The above-mentioned adaptive fender system suitable for LNG siding transportation, further, has a reel speed Vj≥10m / min.

[0019] The above-mentioned adaptive fender system suitable for LNG side-by-side transportation, further, the track support frame is a steel support frame, a plurality of support legs are fixed to the lower surface of the track support frame, and the bottom of the support legs is welded to the deck.

[0020] The above-mentioned adaptive fender system suitable for LNG siding transportation, further, the length of the track support frame is 1.5 to 2 times the length of the automatic cable winch.

[0021] The above-mentioned adaptive fender system suitable for LNG siding transportation further has a track support frame height of not less than 1m and not more than 1.4m.

[0022] The above-mentioned adaptive fender system suitable for LNG siding transportation further comprises a plurality of rollers laid on the bottom of the winch. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the structure of the present invention;

[0024] Figure 2 It is a schematic diagram of the structure of an automatic cable winch;

[0025] Figure 3 It is a schematic diagram of the movable fender structure;

[0026] Figure 4 It is a schematic diagram of the track structure;

[0027] Figure 5 This is a schematic diagram of LNG ship docking;

[0028] Figure 6 is a control logic diagram of the present invention;

[0029] Among them: 11- movable fender, 111- fender body, 112- sonic rangefinder, 113- eye plate, 114- cable, 21- automatic cable winch, 211- winch frame, 212- drum, 214- fairlead, 216- gear box, 217- gear, 218- roller, 31- track, 311- track support frame, 312- rack, 313- limiter, 511- cable fixer, A- floating LNG receiving and processing platform, Ac- LNG ship, B-flat side line of floating LNG receiving and processing platform (parallel to the mid-body range line), Bc-LNG ship width, C-floating LNG receiving and processing platform manifold area, Cc-LNG ship manifold area, Dc-LNG ship berthing draft, Df-inflatable fender diameter, Ds-full load draft, Db-ballast draft, E-inflatable fender absorption energy, Ha-LNG ship effective height, Hb-floating LNG receiving and processing platform effective height, Hg-track support frame height, Lc-rack length, Lf -Inflatable fender length, Lg-track support frame length, Lj-center distance between stern drum and bow drum, Lag-distance at the stern fixed fender sonic rangefinder, Lfg-distance at the bow fixed fender sonic rangefinder, Laf-distance from the stern mobile fender sonic rangefinder to the stern fixed fender sonic rangefinder, Lff-distance from the stern fixed fender sonic rangefinder to the bow fixed fender sonic rangefinder, Lfa-distance from the bow fixed fender sonic rangefinder to the bow mobile fender sonic rangefinder , Lal-theoretical distance from the stern mobile fender sonic rangefinder to the outer plate of the LNG ship, Lfl-theoretical distance from the bow mobile fender sonic rangefinder to the outer plate of the LNG ship, Las-actual distance from the stern mobile fender sonic rangefinder to the LNG ship, Lfs-actual distance from the bow mobile fender sonic rangefinder to the LNG ship, Ma-original position of the stern mobile fender, Mf-original position of the bow mobile fender, α-maximum roll angle of the LNG ship, β-angle between the cable and the axis of the inflatable fender. DETAILED DESCRIPTION

[0030] The present invention will be further described in conjunction with the accompanying drawings.

[0031] like Figure 1 , 2As shown in Figures 3 and 4, an adaptive fender system suitable for LNG siding transportation is installed on a floating LNG receiving and processing platform or FSRU or FLNG. Two movable fenders are located at both ends of the parallel middle body of the floating LNG receiving and processing platform, and two fixed fenders are located at both ends of the manifold area of ​​the floating LNG receiving and processing platform. The movable fender consists of a track and an automatic cable winch. The track is fixed on the deck. The track includes a track support frame and a rack. Limiting parts are set at both ends of the track support frame. When the cable winch at the stern or bow touches the limiting parts, the walking mechanism stops automatically, thereby preventing the cable winch at the stern or bow from derailing. The rack is located in the middle of the track support frame. The track is slidably connected with an automatic cable winch, which includes a winch frame, a gear fixed at the bottom center of the winch frame, the gear meshing with the rack teeth, drums fixed at both ends of the winch frame, and the two drums are coaxially connected. The automatic cable winch is equipped with a gear box, which is connected to the two drum shafts. The gear box is controlled by the first motor, and a cable is wound on the drum, which is fixedly connected to the end of the fender body, and the angle between the cable and the axis of the fender body is 45°≤β≤60°. The first motor drives the gear box to drive the drum to rotate and retract the fender body. A sonic rangefinder is also provided at the end of the fender body, and the sonic rangefinder is fixed near the bow or stern.

[0032] The fixed fender consists of a fender body and a cable holder. The cable holder is fixed on the deck. Cables are connected to both ends of the fender body, and the other end of the cable is connected to the cable holder. The angle between the cable and the axis of the fender body is 45°≤β≤60°.

[0033] like Figure 5 , 6 As shown, when the floating LNG receiving and processing platform needs to carry out LNG transportation operations, the LNG ship gradually approaches the floating LNG receiving and processing platform in an arbitrary posture. In the process of gradually approaching, the acoustic rangefinders of the stern fixed fender and the bow fixed fender start to work. Since the LNG ship cannot always remain parallel to the floating LNG receiving and processing platform during the process of berthing at the floating LNG receiving and processing platform, the distance at the stern fixed fender acoustic rangefinder is Lag, and the distance at the bow fixed fender acoustic rangefinder is Lfg. The two are only the same when the floating LNG receiving and processing platform and the LNG ship are parallel, and they are not the same in most other cases. At the same time, the distance from the stern movable fender acoustic rangefinder to the stern fixed fender acoustic rangefinder is Laf, the distance from the stern fixed fender acoustic rangefinder to the bow fixed fender acoustic rangefinder is Lff, and the distance from the bow fixed fender acoustic rangefinder to the bow movable fender acoustic rangefinder is Lfa.

[0034] The length Lf of the inflatable fender is selected according to the diameter Df of the inflatable fender in accordance with ISO 17357:2002 standard. The center distance between the stern drum and the bow drum Lj = Lf + 2 × Hb × tan45°. The length Lg of the track support frame is between 1.5 and 2 times the center distance Lj between the stern drum and the bow drum, that is, 1.5Lj≤Lg≤2Lj. The height Hg of the track support frame is not less than 1m and not higher than 1.4m, that is, 1m≤Hg≤1.4m, for easy maintenance.

[0035] The rack is installed on the track support frame, and the rack length Lc is not less than twice the length of the inflatable fender Lf, and does not need to be greater than three times Lf, that is, 2Lf≤Lc≤3Lf. The rack length is the stroke of the stern / bow cable winch. 2Lf≤Lc ensures that the stern / bow mobile fender has a sufficient stroke range to adapt to more LNG ship types, especially for smaller ships. Lc≤3Lf makes the stroke of the stern / bow mobile fender not have to exceed an unrealistic length.

[0036] The sonic rangefinder measures the distance from the movable fender to the LNG ship, the horizontal distance. The data measured by the horizontal distance is transmitted to the automatic cable winch, which processes the data.

[0037] The theoretical distance from the mobile fender sonic rangefinder located at the stern to the outer plate of the LNG ship should be Lal:

[0038]

[0039] The theoretical distance from the mobile fender sonic rangefinder located at the bow to the outer plate of the LNG ship is to be Lfl:

[0040]

[0041] At this time, the mobile fender sonic rangefinder at the stern measures the actual distance Las to the LNG ship. If Las>Lal, it means that the mobile fender at the stern is not in the parallel center body of the LNG ship. If Las=Lal, it means that the mobile fender at the stern is in the parallel center body of the LNG ship. Since the hull is always in motion in the ocean, the values ​​of Las and Lal need to be compared continuously. When the result is stable, when Las>Lal, the cable winch at the stern moves toward the middle of the ship, driving the mobile fender at the stern to move toward the middle of the ship, while continuing to measure Las and continue to compare it with Lal. Until the result stabilizes at Las=Lal, the cable winch at the stern stops moving. At this time, the mobile fender at the stern is inside the parallel center body of the floating LNG receiving and processing platform and the LNG ship, and can fully play the role of a fender.

[0042] The mobile fender sonic rangefinder located at the bow measures the actual distance Lfs to the LNG ship. If Lfs>Lfl, it means that the mobile fender located at the bow is not in the parallel center body of the LNG ship. If Lfs=Lfl, it means that the mobile fender located at the bow is in the parallel center body of the LNG ship. Since the hull is always in motion in the ocean, the values ​​of Lfs and Lfl need to be compared continuously. When the result is stable, when Lfs>Lfl, the cable winch located at the bow moves toward the middle of the ship, driving the mobile fender located at the bow to move toward the middle of the ship, while continuing to measure Lfs and continue to compare it with Lfl. Until the result stabilizes at Lfs=Lfl, the cable winch located at the bow stops moving. At this time, the mobile fender located at the bow is inside the parallel center body of the floating LNG receiving and processing platform and the LNG ship, and can fully play the role of a fender.

[0043] After the movement is completed, the mobile fenders located at the bow and the stern remain stationary until the LNG siding transmission operation is completed. After the LNG ship leaves the floating LNG receiving and processing platform, the cable winch located at the stern moves toward the stern, driving the mobile fender located at the stern to move toward the stern to the initial position Ma; the cable winch located at the bow moves toward the bow, driving the mobile fender located at the bow to move toward the bow to the initial position Mf.

[0044] Thus, the working process of the adaptive fender system suitable for LNG side-by-side transportation in the process of an LNG side-by-side transportation operation of the present invention is completed.

Claims

1. An adaptive fender system suitable for LNG siding transportation, characterized in that: A movable fender (11) is fixed at each end of the bow and stern of the parallel mid-body deck of the floating LNG receiving and processing platform, and a fixed fender (41) is fixed at each end of the manifold area of ​​the floating LNG receiving and processing platform; The movable fender comprises a track (31), an automatic cable winch (21) and a fender body (111). The track is fixed on the deck, and comprises a track support frame (311) and a rack (312). Limiting members (313) are arranged at both ends of the track support frame, and the rack is located in the middle of the track support frame. The track is slidably connected with an automatic cable winch, and the automatic cable winch comprises a winch frame (211). A gear (217) is fixed at the bottom center of the winch frame, and the gear is meshed with the rack teeth. Drums (212) are fixed at both ends of the winch frame, and the two drums are coaxially connected. The automatic cable winch is equipped with a gear box (211). 16), a gear box is connected to the two drum shafts, the gear box is controlled by a first motor, a cable (114) is wound on the drum, and both ends of the fender body are fixedly connected to the cable, and the angle between the cable and the axis of the fender body (111) is β, 45°≤β≤60°; an acoustic rangefinder (112) is also provided at the end of the fender body of the movable fender, the fender body is located parallel to the bow of the mid-body deck, and the acoustic rangefinder is fixed at one end close to the bow, and the fender body is located parallel to the stern of the mid-body deck, and the acoustic rangefinder is fixed at one end close to the stern; the length of the fender body is selected according to the diameter of the fender body in accordance with ISO 17357:2002 standard; The fixed fender consists of a fender body and a cable holder, the cable holder is fixed on the deck, cables are connected at both ends of the fender body, the other end of the cable is connected to the cable holder (511), and the angle between the cable and the axis of the fender body is 45°≤β≤60°.

2. The adaptive fender system for LNG siding transportation according to claim 1, characterized in that: The gear is driven by a second motor.

3. The adaptive fender system for LNG siding transportation according to claim 1 is characterized in that: The main body of the fender is an inflatable fender.

4. The adaptive fender system for LNG siding transportation according to claim 1, characterized in that: Eye plates (113) are fixed at both ends of the fender body, and cables are connected to the eye plates.

5. The adaptive fender system for LNG siding transportation according to claim 1 is characterized in that: The winch frame is a steel winch frame.

6. The adaptive fender system for LNG siding transportation according to claim 1, characterized in that: A cable guide hole is arranged at the front end of the drum, and the cable passes through the cable guide hole and is connected to the end of the fender body.

7. The adaptive fender system for LNG siding transportation according to claim 1, characterized in that: Roll speed Vj≥10m / min.

8. The adaptive fender system for LNG siding transportation according to claim 1, characterized in that: The track support frame is a steel support frame, and a plurality of support legs are fixed on the lower surface of the track support frame, and the bottom of the support legs is welded to the deck.

9. The adaptive fender system for LNG siding transportation according to claim 1, characterized in that: The length of the track support frame is 1.5 to 2 times the length of the automatic cable winch, and the height of the track support frame is not less than 1m and not more than 1.4m.

10. The adaptive fender system for LNG siding transportation according to claim 1, characterized in that: A plurality of rollers (218) are also provided at the bottom of the winch.

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