The invention relates to a system for transfer of a fluid product, particularly a liquefied natural gas, between a transport vehicle, such as a ship, and an installation for receiving this product or supplying the ship with this product, which has a device for transferring the product between the ship and the installation, that is supported at a first end by a support structure and has a second end that can be connected to a manifold device of the vehicle.
Known transfer systems for the transfer of liquefied natural gas are not suitable for use under severe environmental conditions.
The present invention offers a system that eliminates the above-mentioned disadvantage of known systems.
To attain this aim, the transfer system according to the invention has a the support structure with a carrier boom for a rigid transfer pipe that is mounted on a mooring post, rotating around a vertical axis above a transport vehicle, and a deformable transfer device, a first end of which is connected to the transfer pipe, and a second end that can be moved between a storage position near the boom and a position of connection to a manifold device of a ship.
According to one feature of the invention, the deformable transfer device is connected to the fixed transfer pipe at the free end of the boom, and the connection of the deformable transfer device to the fixed transfer pipe suspends the deformable transfer device from the boom.
According to another feature of the invention, the mooring post is a single mooring point, and the vehicle can turn freely about the mooring post in order to orient itself in the direction of the elements (swell, wind, current).
According to another feature of the invention, the boom is carried along by the ship by the deformable transfer device when the transfer device is connected to the manifold of the ship.
According to yet another feature of the invention, when the deformable transfer device is not connected to the manifold, the boom is free to orient itself in the direction of the wind in order to resist storms under survival conditions.
According to yet another feature of the invention, braking means in the boom rotational system to avoid an excessive number of small movements.
According to yet another of the invention, the boom and deformable transfer device are configured such that the stresses exerted on the boom pass through its neutral axis so that the boom is subjected only to simple bending.
According to yet another feature of the invention, the deformable transfer device filters the ship movements so that small movements of the ship around its average position do not generate sufficient lateral stress to lead to rotation of the boom, and the device absorbs high frequency movements and avoids stress peaks.
According to yet another feature of the invention, the deformable transfer device is stored under the boom while oriented parallel to the axis of the boom, and is connected to the fixed pipe by a rotating joint that makes possible a rotation into a position perpendicular to the longitudinal axis of ship during establishment of a connection to the manifold of the ship.
According to yet another feature of the invention, the deformable transfer device has, at its free end, a device for connection to the manifold of the ship.
According to yet another feature of the invention, the connection device and the manifold of the ship have means for centering during dynamic connection of the transfer device to the manifold.
According to yet another feature of the invention, the deformable transfer device has a number of pairs of transfer arms, free ends of the inner arms are connected to a shared part connected to the fixed pipe by the rotating joint, and outer arms carrying connectors.
According to yet another feature of the invention, the deformable transfer device has at least one pair of tubular arms which are articulated to one another, namely an inner arm connected to the fixed pipe and an outer arm that carries a connector at a free end.
According to yet another feature of the invention, the deformable transfer device has at least one cryogenic hose that is connected to an end of the fixed transfer pipe and another end carries a connecting device.
According to yet another feature of the invention, the cryogenic hose in a storage position is suspended under the boom at the end that carries the connector and extends as a chain.
According to yet another feature of the invention, a stand-off arm are associated with the cryogenic hose maintains a predetermined separation between the ship and the boom during the transfer of fluid and/or a predetermined radius of curvature of the hose during connection/disconnection.
According to yet another feature of the invention, stand-off arm is connected to the manifold of the ship during transfer of fluid.
According to yet another feature of the invention, the deformable transfer device has a number of cryogenic hoses joined at first ends that are connected to the fixed pipe, and each of which carries a connector at a free end.
According to yet another feature of the invention, the stand-off arm is suspended under the boom by a connecting component, such as a cable or a connecting rod, to form a balance beam that ensures that a predetermined distance between the ship and the boom is maintained during transfer of fluid and that reduces or cancels the stresses exerted on the connectors or manifolds during establishment of a connection and during transfer.
The invention will be better understood, and other aims, characteristics, details and advantages of it will appear more clearly in the following explanatory description given with reference to the appended diagrammatic drawings, given only as examples, illustrating several embodiments of the invention, and in which:
Each of
Each of
Each of
Ship 2 is moored by mooring cable 17 to single mooring point 18 of ring 19 which rotates freely around the axis of the mooring post in the form of column 5, cable 17 being attached at front part 20 of the ship.
Boom 8 is motorized so that it can be maneuvered, but it is capable of rotating freely, which allows it to orient itself in the direction of the wind in the storage position. In transfer configuration, it follows ship 2 in its changes of average position that depend in particular on the direction of the wind, of the current, and of the waves. During a transfer of liquefied natural gas between ship 2 and the fixed installation, boom 8 is carried along by the ship via the intermediary of deformable transfer device 11. By making the resultant of the stresses exerted on the boom pass through the neutral axis of the boom, the boom is subjected only to simple bending stress and not to torsional stress. As will be described hereafter, deformable transfer device 11 is realized in such a way as to produce a filtering of the movements of the ship. The small movements of the latter around its average position do not generate sufficient lateral stress to lead to rotation of the boom. Only the changes of average position of the ship lead to rotation. The device “absorbs” the small movements of the ship. Furthermore, the device is capable of absorbing the stress peaks.
With reference to
A first embodiment of fluid transfer device 11 according to the invention will now be described with reference to
Connecting module 38 which, as seen in the figures, constitutes an extension of the manifolds of the ship, is stored on either the ship or the transfer system. In the latter case, in order for it to be positioned on the manifolds during fluid transfer, the module will be transported to the ship by a service vehicle, for example, or be lowered by a winch from the end of the boom onto the ship.
It should also be noted that, according to the explanations given on the subject of the entrainment of the boom during a fluid transfer, the masses are, as much as possible, brought to the bottom of the inner arm. In order to find an optimum, it will be possible to provide a counterweight at this location as indicated at 41 in
The structure making it possible to maneuver deformable transfer device 11 comprise maneuvering cable 42, which can be wound around winch 43, mounted under boom 8, and whose free end is attached to transfer device 11 at the site of joint 28 between the two arms. This control makes it possible to lower the two arms in a position folded on one another. Another maneuvering cable 45 is provided for unfolding the two arms, one end of cable 45 being windable on or unwindable from winch 46 mounted high on inner arm 25, and the other end of cable 45 being attached at 47 to arm 26 near the free end of the arm 26. The winches can be controlled, in particular remote-controlled, in any appropriate known manner. The rotation of transfer device 11 formed by the three pairs of arms can be controlled, for example, by means of a hydraulic actuator or hydraulic motor, which is not represented. This rotation can also be effected by winching from a service ship. The process for connection of transfer device 11 to manifolds 15 of ship 2 will be described hereafter with reference to
A second embodiment of the fluid transfer system according to the invention will be described hereafter with reference to
Each connector 33 is suspended by a cable 56 which can be wound on winch 57 that is mounted on support cross piece 59, which is itself attached on an arm in the form of a bar 60 that is intended for maintenance of a minimum separation between the ship and boom 8. In effect, when the transfer hoses are arranged in the manner of chains between the end of boom 8 and manifolds 15 as in the present case, the horizontal components of the tensions tend to bring the boom toward the ship. Furthermore, bar 60 participates in putting boom 8 in rotation according to the principle already described. This bar carries, at an end opposite from the end carrying cross piece 59, another cross piece 61 whose exterior longitudinal surface carries projecting elements 63 delimiting between one another three V-shaped seats 64, each intended to receive a hose 50. At each end, cross piece 61 has projecting lateral lugs 65 for keeping the hoses near their seat 64. Stand-off bar 60 is suspended at its front end by cable 67 and at its rear end by two cables 68 from transverse beam 70 that also carries E-shaped part 30 to which the three hoses are connected, each cable 68 extending between an end of beam 70 and an end of crosspiece 61. Each hose is moreover provided, in the part situated between cross piece 61 and part 70, with spacers 72. It is also observed that the front end of stand-off bar 60 carries spindle 74 that is mounted to pivot on two ball joints (three directions of rotation) and is intended to cooperate with complementary funnel 75 mounted on connecting module 38, through a cable 76, which can be wound on a winch 77. The winch 77 is also provided on the connecting module. Of course, this module carries winches for winding the cables for engagement and for maintaining the spindles of connectors 33 in their associated funnel, as in the case of the first embodiment.
Transfer device 11 formed by the set of hoses 50 can be maneuvered by two maneuvering cables attached to the front and rear ends of stand-off arm 60, namely front cable 80 that can be wound on winch 81 mounted under boom 8, and two cables 83 that can be wound on two winches 84 also arranged under the boom. The two winches 81 and 84 are separated from one another in the longitudinal direction of the boom. It is also important to note that arm 60 can be provided, at its rear end, with counterweight 86 according to the principle already described. It is also possible to provide each hose 50 with curvature stiffeners 87 and 88 at, respectively, its upper end and at its intermediate curved part intended to butt against cross piece 61 when the hoses are connected to the manifolds of the ship, as seen in
In order to connect the hoses to the manifold of a ship, maneuvering cables 80 and 83 are unwound, as seen in
According to
It is observed that the suspension by cable 68 of arms 103 near its middle zone and the counterweight ensure a stable state of equilibrium and moreover make it possible to reduce the maneuvering stresses during connection to the manifolds of the ship, and the stresses on the manifolds or the manifold extensions. Of course, this effect is also produced in a more or less pronounced way in the other embodiments.
It emerges from the description that the invention offers a transfer system that, while having a simple structure, is completely suitable for operation under severe environmental conditions. Thanks to the use of a boom, the transfer system can have a single mooring point while being applicable to ships whose manifolds extend perpendicular to the longitudinal axis of the ship and in its middle (standard liquid natural gas tankers). Of course, these manifolds need not be arranged in the central part of the ship, as in the case which is represented. It should be noted that the transfer system according to the invention can be realized in the form of an off-shore station.
Of course, numerous modifications can be made to the embodiments described and represented without departing from the scope of the invention. Thus, the support of the boom could be installed on a floating support, such as a floating unit for storage or production of liquefied natural gas. In the preceding description, the LNG transfer lines alone were described. It is also possible, of course, to provide a circuit for the return of gas in the form of vapor. In this case, it will be advantageous to use rotating multi-passage coaxial fluid joints in the axis of rotation of the boom in the mooring column. The same is true for joint 31 for connecting the deformable transfer device to the rigid pipe. Concerning joint 31, 360° rotation not being necessary, either rotating single-passage joints on the same axis, or hoses could advantageously be used. Such joints are known, and need not be described here.
In the embodiments described and represented, the deformable transfer devices are connected to the manifold device from below. It would of course be possible to provide transfer devices that are connected to the manifold from above, that is to say, by lowering. In this case, it is sufficient to make the connectors of the transfer device open, if applicable, towards the bottom and the connectors of the manifold device open towards the top, vertically, the spindle and the funnel extending correspondingly, parallel to the axes of the connectors.
In order to give some indications as to the dimensions of the system according to the invention, only as an example, the boom could advantageously have a length between 200 and 220 meters, and its height above the level of the water could be on the order of 50 meters.
It should be noted that an essential characteristic of the invention lies in the fact that during the sensitive phases of connection/disconnection of the deformable transfer device, a single cable executes the functions of support/hoisting of the mobile end of this deformable system and of guiding, in particular, laterally. This single cable is arranged along the axis of the main movements of the ship (heaving).
Number | Date | Country | Kind |
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01 06279 | May 2001 | FR | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/FR02/01603 | 5/13/2002 | WO | 00 | 4/7/2004 |
Publishing Document | Publishing Date | Country | Kind |
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WO02/092494 | 11/21/2002 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
2922446 | Sheiry | Jan 1960 | A |
3349816 | Mowell et al. | Oct 1967 | A |
4090538 | Kotcharian | May 1978 | A |
4261398 | Haley | Apr 1981 | A |
6623043 | Pollack | Sep 2003 | B1 |
6637479 | Eide et al. | Oct 2003 | B1 |
Number | Date | Country | |
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20040154697 A1 | Aug 2004 | US |