CN114929572B - Ship liquefied gas supply system and method and ship liquefied gas fuel supply system - Google Patents
Ship liquefied gas supply system and method and ship liquefied gas fuel supply system Download PDFInfo
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- CN114929572B CN114929572B CN202080086411.0A CN202080086411A CN114929572B CN 114929572 B CN114929572 B CN 114929572B CN 202080086411 A CN202080086411 A CN 202080086411A CN 114929572 B CN114929572 B CN 114929572B
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- gas
- line
- liquefied gas
- lng
- boil
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- 238000000034 method Methods 0.000 title claims abstract description 131
- 239000000446 fuel Substances 0.000 title abstract description 50
- 238000007599 discharging Methods 0.000 claims abstract description 35
- 239000007789 gas Substances 0.000 claims description 547
- 239000007788 liquid Substances 0.000 claims description 244
- 238000002955 isolation Methods 0.000 claims description 67
- 239000011261 inert gas Substances 0.000 claims description 57
- 238000010438 heat treatment Methods 0.000 claims description 10
- 238000007872 degassing Methods 0.000 claims description 9
- 238000011144 upstream manufacturing Methods 0.000 claims 4
- 239000002828 fuel tank Substances 0.000 abstract description 172
- 238000012545 processing Methods 0.000 abstract description 3
- 239000003949 liquefied natural gas Substances 0.000 description 326
- 238000001816 cooling Methods 0.000 description 61
- 239000012530 fluid Substances 0.000 description 18
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 16
- 238000001704 evaporation Methods 0.000 description 14
- 230000008020 evaporation Effects 0.000 description 14
- 238000011049 filling Methods 0.000 description 11
- 239000003345 natural gas Substances 0.000 description 8
- 238000012360 testing method Methods 0.000 description 8
- 238000012546 transfer Methods 0.000 description 6
- 238000002485 combustion reaction Methods 0.000 description 4
- 238000004891 communication Methods 0.000 description 4
- 238000001035 drying Methods 0.000 description 4
- 238000002347 injection Methods 0.000 description 4
- 239000007924 injection Substances 0.000 description 4
- 238000010248 power generation Methods 0.000 description 4
- 238000004880 explosion Methods 0.000 description 3
- 238000004064 recycling Methods 0.000 description 3
- 238000009834 vaporization Methods 0.000 description 3
- 230000008016 vaporization Effects 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- 239000000969 carrier Substances 0.000 description 2
- 239000000470 constituent Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000006073 displacement reaction Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000007667 floating Methods 0.000 description 2
- 239000003915 liquefied petroleum gas Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- OTMSDBZUPAUEDD-UHFFFAOYSA-N Ethane Chemical compound CC OTMSDBZUPAUEDD-UHFFFAOYSA-N 0.000 description 1
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 1
- 239000005977 Ethylene Substances 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 239000012159 carrier gas Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000003912 environmental pollution Methods 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- -1 for example Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 125000004435 hydrogen atom Chemical class [H]* 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 description 1
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING
- B63B25/00—Load-accommodating arrangements, e.g. stowing, trimming; Vessels characterised thereby
- B63B25/02—Load-accommodating arrangements, e.g. stowing, trimming; Vessels characterised thereby for bulk goods
- B63B25/08—Load-accommodating arrangements, e.g. stowing, trimming; Vessels characterised thereby for bulk goods fluid
- B63B25/12—Load-accommodating arrangements, e.g. stowing, trimming; Vessels characterised thereby for bulk goods fluid closed
- B63B25/16—Load-accommodating arrangements, e.g. stowing, trimming; Vessels characterised thereby for bulk goods fluid closed heat-insulated
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING
- B63B27/00—Arrangement of ship-based loading or unloading equipment for cargo or passengers
- B63B27/30—Arrangement of ship-based loading or unloading equipment for transfer at sea between ships or between ships and off-shore structures
- B63B27/34—Arrangement of ship-based loading or unloading equipment for transfer at sea between ships or between ships and off-shore structures using pipe-lines
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63J—AUXILIARIES ON VESSELS
- B63J2/00—Arrangements of ventilation, heating, cooling, or air-conditioning
- B63J2/02—Ventilation; Air-conditioning
- B63J2/08—Ventilation; Air-conditioning of holds
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C13/00—Details of vessels or of the filling or discharging of vessels
- F17C13/04—Arrangement or mounting of valves
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C6/00—Methods and apparatus for filling vessels not under pressure with liquefied or solidified gases
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C9/00—Methods or apparatus for discharging liquefied or solidified gases from vessels not under pressure
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Ocean & Marine Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Filling Or Discharging Of Gas Storage Vessels (AREA)
Abstract
The present invention relates to a liquefied gas supply system and method. The liquefied gas supply system and method can treat the boil-off gas generated when the liquefied gas is supplied to the storage tank of the ship without returning the boil-off gas to the outside. In addition, the invention relates to a marine liquefied gas fuel supply system. The liquefied gas fuel supply system for a ship is capable of processing a boil-off gas generated when a liquefied gas fuel is supplied to a fuel tank of the ship in the ship without returning the boil-off gas to the outside. The liquefied gas supply system according to the present invention, as a system for supplying liquefied gas from a liquefied gas supply vessel to a vessel including a plurality of liquefied gas storage tanks, includes: a liquefied gas line for supplying liquefied gas from the liquefied gas supply vessel to any one of the plurality of liquefied gas storage tanks; a gas discharge line for discharging a boil-off gas generated when the liquefied gas is supplied to the one of the liquefied gas storage tanks; and a gas supply line for supplying the boil-off gas to one or more other liquefied gas storage tanks.
Description
Technical Field
The present invention relates to a liquefied gas supply system and method capable of processing a boil-off gas generated when a liquefied gas is supplied to a storage tank of a ship in the ship without returning the boil-off gas to the outside.
The present invention also relates to a ship liquefied gas fuel supply system capable of processing a boil-off gas generated when a liquefied gas fuel is supplied to a ship fuel tank in a ship without returning the boil-off gas to the outside.
Background
Typically, natural gas is produced in the form of Liquefied Natural Gas (LNG) at a production site and then transported by an LNG carrier to a natural gas receiving station on land.
Empty LNG storage tanks provided on board of the ship are typically filled with inert gas to prevent gas explosion. That is, a replacement process of replacing inert gas filled in the storage tank with natural gas is performed in a commissioning phase before operating the LNG carrier or before storing LNG in the LNG storage tank of the LNG carrier.
In addition, after the replacement process, a cooling process is performed to reduce the temperature inside the tank, and then LNG may be supplied into the tank.
Meanwhile, when a cooling process is performed and LNG is supplied, a large amount of boil-off gas is generated, which is generally returned to a gas receiving station to maintain the pressure in the tank.
For example, about 4 to 7MT/hr of boil-off gas is produced in the cooling process stage and about 7 to 9MT/hr of boil-off gas is produced in the LNG supply stage. In the LNG supply, as described above, the boil-off gas of about 4 to 9MT/hr is returned from the ship to the gas receiving station at each stage, and the returned boil-off gas is recovered by reliquefaction or treated by combustion in GCU (gas combustion unit).
Disclosure of Invention
Technical problem to be solved
In addition, as a countermeasure against the environmental pollution problem, the operation of LNG refueling ships has become active as LNG fuel ships expand in popularity. The LNG refueling ship is a ship that travels to a place where the LNG ship is operated and supplies LNG from the LNG refueling ship to the LNG fueling ship at sea.
Similarly, when LNG is supplied from an LNG-carrier to an LNG-fuelled ship, a large amount of boil-off gas is also generated in the LNG-fuelled ship receiving LNG.
Since LNG fuel ships are loaded with cargo, it is not easy to install a pipeline to recover boil-off gas, and the boil-off gas is a flammable substance, thus risking fire or explosion. Preferably, the boil-off gas generated when the LNG is supplied is recovered from the LNG fueller and then treated in the LNG refueling ship.
An empty LNG fuel tank is typically filled with an inert gas prior to receiving the LNG fuel to prevent gas explosion. That is, in a test operation stage before starting to operate the LNG fuel ship, or before storing the LNG fuel in an empty LNG fuel tank, a replacement process of replacing inert gas filled in the tank with natural gas is required.
In addition, after the replacement process, a cooling process of lowering the internal temperature of the fuel tank is performed, and then LNG may be supplied to the fuel tank.
On the other hand, when performing a cooling process and supplying LNG, a large amount of boil-off gas is generated, which is typically returned to a gas receiving station to maintain the pressure within the tank.
A technology of supplying LNG to various LNG vessels including LNG storage tanks such as LNG fuel tanks (for example, a technology of supplying LNG for test operation to an LNG carrier) using the LNG refueling vessels in addition to supplying LNG fuel to the LNG fuel vessels at sea has been actively discussed.
As described above, in order to supply LNG to an empty LNG storage tank of an LNG carrier to be commissioned, a replacement process and a cooling process need to be performed first. That is, in order to supply LNG for test operation to the LNG carrier by the LNG refueling ship, it is necessary to directly process the boil-off gas recovered from the LNG carrier at each stage in the LNG refueling ship at about 4 to 9 MT/hr.
But the GCU capacity of lng tankers is limited. In fact, in the case of LNG-filled vessels having LNG-filling function being built in korea, and LNG-filled vessels actually being built by korea shipyards and operated in european ports, GCU capacity is less than 1 ton.
In addition, since the LNG carrier in the commissioning phase does not yet have an operating state of the GCU or the reliquefaction device capable of handling the boil-off gas, it can be said that the boil-off gas cannot be handled by the LNG carrier itself.
As described above, practically, all the boil-off gas generated during cooling and supply cannot be handled without discharging the boil-off gas into the atmosphere.
Accordingly, an object of the present invention is to solve the above-described problems and to provide a ship liquefied gas supply system and method capable of automatically handling LNG in an LNG carrier without recovering boil-off gas generated when LNG is supplied to an LNG storage tank of the LNG carrier or LNG used for test operation to an LNG filling ship.
The present invention also provides a ship liquefied gas fuel supply system capable of automatically handling LNG fuel vessels without recovering boil-off gas generated when LNG is supplied to LNG fuel tanks of the LNG fuel vessels to the LNG filling vessels.
Means for solving the problems
To achieve the above object, according to one aspect of the present invention, there is provided a liquefied gas supply system for supplying liquefied gas from a liquefied gas supply vessel to a vessel including a plurality of liquefied gas storage tanks, comprising: a liquefied gas line for supplying liquefied gas to any one of the plurality of liquefied gas storage tanks; a gas discharge line for discharging a boil-off gas generated by supplying a liquefied gas to any one of the liquefied gas storage tanks; a gas supply line for supplying the boil-off gas to one or more other liquefied gas storage tanks.
Preferably, a heater for heating the boil-off gas discharged along the gas discharge line may be further included, and the boil-off gas heated at the heater may be supplied to one or more other liquefied gas storage tanks through the gas supply line.
Preferably, the boil-off gas generated when the liquefied gas is supplied to the any one of the liquefied gas storage tanks may be supplied to the other liquefied gas storage tank.
Preferably, the boil-off gas generated when the liquefied gas is supplied to any one of the liquefied gas storage tanks may be supplied to all of the other liquefied gas storage tanks remaining.
Preferably, the liquefied gas line connects the liquefied gas supply vessel and the liquefied gas storage tank, and may include: a liquid crossover line for transporting liquefied gas from the liquefied gas supply vessel; a liquid line for branching and supplying the received liquefied gas to each liquefied gas storage tank through the liquid crossover line.
Preferably, the liquid line may further comprise one or more isolation valves for isolating the liquid line such that when liquefied gas is supplied through the liquid crossover line, liquefied gas is not supplied to one or more other liquefied gas storage tanks.
Preferably, the isolation valve may be installed between a point where the liquid crossover line and the liquid line intersect and a point branching from the point to the first intersecting liquefied gas storage tank.
In order to achieve the above object, according to another aspect of the present invention, there is provided a method of supplying liquefied gas from a liquefied gas supply vessel to a vessel including a plurality of liquefied gas storage tanks, the liquefied gas supply method including the steps of: a liquefied gas supply step of supplying liquefied gas from a liquefied gas supply vessel to any one of the plurality of liquefied gas storage tanks; a boil-off gas discharging step of discharging a boil-off gas generated by supplying a liquefied gas to any one of the liquefied gas storage tanks; a replacement gas supply step of supplying the boil-off gas discharged from any one of the liquefied gas storage tanks to one or more other liquefied gas storage tanks among the plurality of liquefied gas storage tanks.
Preferably, the boil-off gas discharged in the boil-off gas discharging step may be heated, and the heated boil-off gas may be supplied to one or more other liquefied gas storage tanks.
Preferably, the boil-off gas generated when the liquefied gas is supplied to any one of the liquefied gas storage tanks may be supplied to the other liquefied gas storage tank.
Preferably, the boil-off gas generated when the liquefied gas is supplied to any one of the liquefied gas storage tanks may be supplied to all of the other liquefied gas storage tanks remaining.
Preferably, when liquefied gas is supplied to any one of the liquefied gas storage tanks, it may be shut off so that liquefied gas is not supplied to one or more other liquefied gas storage tanks.
According to another aspect of the present invention for achieving the above object, there is provided a supply method of supplying liquefied gas for a ship commissioning from a liquefied gas supply ship to a liquefied gas carrier ship including a plurality of liquefied gas storage tanks, the liquefied gas supply method for a ship commissioning comprising the steps of: a step of supplying liquefied gas for cooling, from the liquefied gas supply vessel, to a storage tank to be cooled, which is ready to perform a cooling process, among the plurality of liquefied gas storage tanks, by using a gas stripping line for injection to the liquefied gas storage tank; a step of discharging a cooling boil-off gas, in which the boil-off gas generated in the storage tank to be cooled when the liquefied gas is supplied to the storage tank to be cooled is discharged through a gas line provided for discharging from the liquefied gas storage tank; and a step of supplying a first replacement gas for supplying the evaporated gas discharged from the storage tanks to be cooled to a first replacement storage tank to be subjected to a replacement process among the plurality of liquefied gas storage tanks.
Preferably, the method may further include the step of discharging a first inert gas, the first replacement storage tank being filled with an inert gas, the inert gas discharged from the first replacement storage tank being supplied to the exhaust tower through a liquid line provided for storing the liquefied gas in or discharging the liquefied gas from the liquefied gas storage tank, and a second connection line connecting the liquid line and the exhaust tower.
Preferably, the step of supplying the first replacement gas may further include a vapor gas treatment step of compressing and heating the vapor gas discharged from the storage tank to be cooled before being supplied to the first replacement storage tank.
Preferably, the amount of the evaporation gas discharged from the storage tank to be cooled is equal to or greater than the amount of the evaporation gas required for the replacement process of the first storage tank to be replaced, which may be completed when the cooling of the storage tank to be cooled is completed.
Preferably, the method may comprise the steps of: a liquefied gas supply step of, when cooling of the storage tank to be cooled is completed, preparing the storage tank to be cooled to store liquefied gas, and supplying the liquefied gas to the storage tank to be supplied, which is prepared to store the liquefied gas, using a liquid line provided for storing or discharging the liquefied gas in or from the liquefied gas storage tank; a boil-off gas discharging step of discharging a boil-off gas generated in the storage tank to be supplied while supplying a liquefied gas to the storage tank to be supplied through the gas line; and a step of supplying a second replacement gas, the evaporation gas discharged in the evaporation gas discharging step being supplied to a second storage tank to be replaced, which is ready for a replacement process, among the plurality of liquefied gas storage tanks.
Preferably, the method may further include the step of discharging a second evaporation gas, the second storage tank to be replaced being filled with an inert gas, the inert gas discharged from the second storage tank to be replaced by supplying the evaporation gas to the second storage tank to be replaced, the inert gas being supplied to the exhaust tower by a second connection line connecting the liquid line and the exhaust tower.
Preferably, the liquid line is connected to the tank to be supplied through a first liquid line, the liquid line and the second tank to be replaced are connected through a third liquid line, and an isolation valve is provided between a point where the first liquid line branches from the liquid line and a point where the third liquid line branches, and the isolation valve may be closed in the step of discharging the second replacement gas.
Preferably, the supplying the second replacement gas may further include a second boil-off gas treatment step of compressing and heating the boil-off gas discharged from the storage tank to be supplied before supplying the second storage tank to be replaced.
In addition, in order to achieve the above object, according to another aspect of the present invention, there is provided a liquefied gas supply system for ship commissioning, which supplies liquefied gas for commissioning from a liquefied gas supply ship to a liquefied gas carrier ship including a plurality of liquefied gas storage tanks, the liquefied gas supply system for ship commissioning comprising: a gas stripping line configured to spray the liquefied gas from the liquefied gas supply vessel to the liquefied gas storage tank, and to transfer the liquefied gas for cooling to a storage tank to be cooled, in which a cooling process is to be performed, among the plurality of liquefied gas storage tanks; a liquid line configured to store the liquefied gas in the liquefied gas storage tank or discharge the liquefied gas from the liquefied gas storage tank, for delivering the liquefied gas for test run to the storage tank to be supplied, which is ready to store the liquefied gas after completion of cooling; and a gas line configured to discharge gas from the liquefied gas storage tank for discharging evaporated gas generated at the to-be-cooled storage tank or the to-be-supplied storage tank when the liquefied gas is supplied to the to-be-cooled storage tank or the to-be-supplied storage tank. And the evaporated gas discharged from the storage tanks to be cooled and the storage tanks to be supplied is conveyed to a storage tank to be replaced, which is prepared for implementing a replacement process, in the plurality of liquefied gas storage tanks through the gas stripping pipeline.
Preferably, the method may further include a second connection line connecting the liquid line and the degassing tower, the storage tank to be replaced being filled with an inert gas, the inert gas discharged from the storage tank to be replaced when the evaporation gas is supplied to the storage tank to be replaced being transferred to the degassing tower through the liquid line and the second connection line.
Preferably, it comprises: a liquid branch line for connecting the liquid line with the storage tank to be cooled or the storage tank to be supplied; and a liquid branch line for replacement for connecting the liquid line with the tank to be replaced. The present invention may further include an isolation valve provided between a point where the liquid branch line branches from the liquid line and a point where the replacement liquid branch line branches, and isolating a path of the liquid line through which the liquefied gas supplied to the tank to be cooled or the tank to be supplied flows and a path of the liquid line through which the inert gas discharged from the tank to be replaced flows from each other by opening and closing control.
In order to achieve the above object, according to an aspect of the present invention, there is provided a liquefied gas supply system for supplying liquefied gas from a liquefied gas supply vessel to a vessel including a plurality of liquefied gas storage tanks, the liquefied gas supply system comprising: a liquefied gas line for supplying liquefied gas from the liquefied gas supply vessel to any one of the plurality of liquefied gas storage tanks; a gas supply line for discharging a boil-off gas generated when a liquefied gas is supplied to any one of the liquefied gas storage tanks and supplying the same to the one or more other liquefied gas storage tanks. Further comprising an isolation valve that causes gas discharged from the liquefied gas storage tank that receives the boil-off gas to be discharged using the liquefied gas line, the isolation valve is provided in a liquefied gas line between a liquefied gas storage tank that receives liquefied gas through the liquefied gas line and a liquefied gas storage tank that receives the boil-off gas, and cuts off the flow of the liquefied gas and the boil-off gas flowing along the liquefied gas line without mixing them.
Preferably, further comprising, a manifold; and a crossover line connecting the manifold and the liquefied gas line, wherein the isolation valve may be a three-way valve disposed at a place where the crossover line and the liquefied gas line intersect.
Preferably, the liquefied gas storage device further comprises a heater for heating the liquefied gas discharged along the gas discharge line, and the liquefied gas heated by the heater may be supplied to one or more other liquefied gas storage tanks through the gas supply line.
Preferably, the gas discharged from the liquefied gas storage tank receiving the boil-off gas is an inert gas, further comprising a connection line for connecting the liquefied gas line and the degassing tower, wherein the inert gas may be transferred from the liquefied gas storage tank to the degassing tower.
In order to achieve the above object, according to another aspect of the present invention, there is provided a liquefied gas supply method of supplying liquefied gas from a liquefied gas supply vessel to a vessel including a plurality of liquefied gas storage tanks, the liquefied gas supply method including the steps of: a liquefied gas supply step of supplying liquefied gas from a liquefied gas supply vessel to any one of the plurality of liquefied gas storage tanks; a boil-off gas discharging step of discharging a boil-off gas generated when the liquefied gas is supplied to the one of the liquefied gas storage tanks; a replacement gas supply step of supplying the boil-off gas discharged from the any one of the liquefied gas storage tanks to one or more other liquefied gas storage tanks among the plurality of liquefied gas storage tanks; and an inert gas discharging step of discharging inert gas filled in the liquefied gas storage tank receiving the boil-off gas due to receipt of the boil-off gas, wherein the inert gas is discharged through a line supplying the liquefied gas to the liquefied gas storage tank.
Preferably, the inert gas discharging step may further include an isolating step of isolating a portion where the liquefied gas flows to the liquefied gas storage tank and a portion where the inert gas flows from each other in a line that supplies the liquefied gas to the liquefied gas storage tank.
Preferably, the boil-off gas discharged in the boil-off gas discharging step may be heated, and the heated boil-off gas may be supplied to one or more other liquefied gas storage tanks.
In order to achieve the above object, according to another aspect of the present invention, there is provided a liquefied gas supply system for ship commissioning, which supplies liquefied gas for commissioning from a liquefied gas supply ship to a liquefied gas carrier ship including a plurality of liquefied gas storage tanks, in which each of the plurality of liquefied gas storage tanks is provided with: a liquid branch line for transporting liquefied gas; a stripping branch line for injecting liquefied gas; and a gas branch line for conveying the boil-off gas. And comprises: a gas line connecting the each gas branch line; and a liquid line connecting the each liquid branch line. The plurality of liquefied gas storage tanks are filled with an inert gas, and include: a storage tank to be replaced to which a replacement process is to be performed; and preparing a storage tank for receiving liquefied gas after the replacement process is completed. Further comprising an isolation valve for controlling a path for supplying liquefied gas by using a liquid branch line or a gas extraction line connected to the storage tank to be received with liquefied gas while allowing vaporized gas discharged from the storage tank to be received with liquefied gas to be transferred to the storage tank to be replaced through the gas line, and allowing inert gas filled in the storage tank to be replaced to be discharged through the liquid branch line provided to the storage tank to be replaced.
Preferably, the liquid cross line is connected with the manifold of the liquefied gas carrier vessel, and the isolation valve may be a three-way valve disposed at a place where the liquid line and the liquid cross line are connected.
Preferably, the isolation valve may be disposed between a point where the liquid branch line of the storage tank ready to receive liquefied gas is connected to the liquid line and a point where the liquid branch line of the storage tank to be replaced is connected to the liquid line.
Preferably, the gas line includes: a compressor for compressing the boil-off gas; and heating the boil-off gas compressed by the compressor, whereby the boil-off gas transferred from the storage tank to be supplied to the tape replacement storage tank can be compressed and heated and supplied.
Preferably, the storage tank ready to receive liquefied gas comprises: the storage tank to be cooled is an object for implementing a cooling process after the replacement process is completed; and a storage tank to be supplied, which is an object of the cooling process to be performed with the liquefied gas supply process for test run, so that the storage tank to be cooled may receive the liquefied gas through the gas stripping branch line, and the storage tank to be supplied may receive the liquefied gas through the liquid branch line.
Preferably, the storage tank to be replaced includes: a first replacement storage tank that receives the boil-off gas from the storage tank to be cooled; and a second replacement storage tank that receives the boil-off gas from the storage tank to be supplied.
In order to achieve the above object, according to an aspect of the present invention, there is provided a system for supplying liquefied gas fuel from a liquefied gas supply vessel to a liquefied gas fuel vessel including two or more liquefied gas fuel tanks, the liquefied gas fuel supply system of the vessel including: a first fuel tank for storing liquefied gas fuel; and a second fuel tank for storing liquefied gas fuel, whereby the liquefied gas fuel is supplied from the liquefied gas supply vessel using a liquid branch line or a gas stripping branch line connected to the first fuel tank, and simultaneously, the boil-off gas discharged from the first fuel tank is supplied as a displacement gas to the second fuel tank through a gas line.
Preferably, in the gas line is provided: a compressor for compressing the boil-off gas; and a heater for heating the boil-off gas compressed by the compressor, so that the boil-off gas transferred from the first fuel tank to the second fuel tank can be compressed and heated and then supplied.
Preferably, it may further include: a liquid line for connecting each of the liquid branch lines; an isolation valve is provided between a point where the liquid branch line of the first fuel tank branches from the liquid line and a point where the liquid branch line of the second fuel tank branches from the liquid line.
Preferably, when liquefied gas is supplied to the first fuel tank using the liquid branch line, gas discharged from the second fuel tank is discharged through the liquid branch line connected to the second fuel tank, and the isolation valve may be closed.
Preferably, a first connection line may be further included for connecting the liquid branch line of the second fuel tank and the rear end of the isolation valve.
Preferably, when the liquefied gas is supplied to the first fuel tank through the liquid branch line, the gas discharged from the second fuel tank may be discharged to the exhaust tower through the liquid line and the first connection line.
Effects of the invention
According to the ship liquefied gas supply system and method and the ship liquefied gas fuel supply system of the present invention, when LNG is supplied to an LNG storage tank (e.g., an LNG fuel tank of an LNG carrier or an LNG fuel ship, etc.), boil-off gas generated in the LNG storage tank can be handled by itself in the LNG carrier without being recovered to an LNG supply site.
In particular, when LNG is to be supplied during a test run of an LNG carrier or in a state where an LNG storage tank is empty, boil-off gas generated when the LNG cooling process and the LNG supply process are performed does not have to be recovered into the LNG refueling ship, but is handled by itself in the LNG carrier or the LNG carrier.
Accordingly, LNG for test operation can be supplied to the LNG carrier or the LNG fueller by using the LNG refueling ship at sea.
In addition, there is no need to forcibly gasify LNG in the replacement process.
In addition, boil-off gas treatment and LNG supply may be simultaneously performed on the LNG-supplying vessel.
Drawings
Fig. 1 is a conceptual diagram schematically illustrating a liquefied gas supply system according to an embodiment of the present invention.
Fig. 2 is a view showing a fluid flow state when cooling a fourth tank of the liquefied gas supply system according to an embodiment of the present invention.
Fig. 3 is a view showing a fluid flow state when cooling a fourth tank of a liquefied gas supply system according to another embodiment of the present invention.
Fig. 4 is a view showing a fluid flow state when LNG is supplied to a fourth tank of a liquefied gas supply system according to an embodiment of the present invention.
Fig. 5 is a view showing a fluid flow state when LNG is supplied to a fourth tank of a liquefied gas supply system according to another embodiment of the present invention.
Fig. 6 is a conceptual diagram schematically illustrating a liquefied gas fuel supply system for a ship according to an embodiment of the present invention.
Fig. 7 is a view showing a fluid flow state when cooling a first fuel tank of a ship liquefied gas fuel supply system according to an embodiment of the present invention.
Fig. 8 is a view showing a fluid flow state when cooling a first fuel tank of a marine liquefied gas fuel supply system according to another embodiment of the present invention.
Fig. 9 is a view showing a fluid flow state when LNG is supplied to a first fuel tank of a ship liquefied gas fuel supply system according to an embodiment of the present invention.
Fig. 10 is a view showing a flow state of fluid when LNG is supplied to a first fuel tank of a liquefied gas fuel supply system of a ship according to another embodiment of the present invention.
Detailed Description
For a full understanding of the operational advantages of the invention, and the objects attained by practicing the invention, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated preferred embodiments of the invention.
The constitution and function of the preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. In the case where reference is made to the constituent elements of each drawing, it should be noted that the same constituent elements are denoted by the same reference numerals as far as possible although they are denoted by different drawings. In addition, the following embodiments may be changed into various forms, and the scope of the present invention is not limited to the following embodiments.
In an embodiment of the present invention described later, the liquefied gas may be a liquefied gas that is liquefied and transportable at low temperature, for example, LNG (liquefied natural gas), LEG (liquefied ethane), LPG (liquefied petroleum gas), liquefied ethylene, liquefied propylene, or the like; or may be a liquid gas such as liquefied carbon dioxide, liquefied hydrogen, or liquefied ammonia, etc. However, in the examples described later, LNG, which is a representative liquefied gas, will be described as an example.
In the following embodiments, an LNG carrier (LNG CARRIER) for transporting LNG as cargo is described as an example, but the present invention can be applied to all offshore structures and vessels such as LNG FSRU (floating storage regasification facility), LNG FPSO (floating production storage offloading facility), LNG RV (reliquefaction vessel) and the like having an LNG storage tank or an LNG fuel vessel having an engine using liquefied gas as fuel.
In the embodiments described later, the storage tank is a concept including all cargo tanks, fuel tanks, and the like, regardless of the name, as long as it is a tank for storing liquefied gas.
Hereinafter, a ship liquefied gas supply system and method and a ship liquefied gas fuel supply system according to an embodiment of the present invention will be described with reference to fig. 1 to 10.
A ship according to an embodiment of the present invention includes: a plurality of LNG storage tanks (T1, T2, T3, T4); a manifold for connecting a ship or a receiving station for supplying LNG, such as an LNG filling station for supplying LNG to a plurality of LNG storage tanks (T1, T2, T3, T4); and a fluid transfer tube for connecting the manifold and the plurality of LNG storage tanks (T1, T2, T3, T4).
The fluid delivery tube includes: a liquefied gas line that supplies liquefied gas from the LNG supply vessel to one of the plurality of LNG storage tanks; a gas discharge line discharging boil-off gas generated by supplying LNG to any one of the LNG storage tanks; and a gas supply line that supplies boil-off gas to one or more other LNG storage tanks.
In the present embodiment described later, the liquefied gas line may refer to a Liquid Line (LL), liquid branch lines (LL 1, LL2, LL3, LL 4), a Stripping Line (SL), and stripping branch lines (SL 1, SL2, SL3, SL 4).
In addition, the gas discharge line may refer to a Gas Line (GL), a gas branch line (GL 1, GL2, GL3, GL 4), and first and second connection lines (CL 1, CL 2), or a Liquid Line (LL) and liquid branch lines (LL 1, LL2, LL3, and LL 4) when gas flows along the Liquid Lines (LL) and the liquid branch lines (LL 1, LL2, LL3, and LL 4).
In addition, the gas supply line may refer to a Gas Line (GL) and gas branch lines (GL 1, GL2, GL3, and GL 4).
In the present embodiment, an example is described in which a ship is connected to an LNG refueling ship, and LNG is supplied from the LNG refueling ship to LNG storage tanks (T1, T2, T3, and T4) through a manifold.
In addition, in the embodiments of the present invention, an example is described in which LNG is supplied from an LNG refueling ship for the purpose of ship commissioning for initial cooling and commissioning of an LNG storage tank. However, the present invention is not limited thereto, and in the case of an LNG ship equipped with two or more LNG tanks, in which case the LNG tanks thereof are supplied with LNG, for example, LNG is supplied to an LNG fuel tank or an LNG storage tank of the LNG ship, or the like, it may be applied in various ways in any case.
In addition, although not shown in the drawings, the ship according to the present embodiment may include: a main engine that generates propulsion energy using LNG stored in LNG storage tanks (T1, T2, T3, T4) as fuel; a power generation engine that generates electric power from LNG stored in LNG storage tanks (T1, T2, T3, T4) as fuel; a fuel supply unit for supplying boil-off gas generated by natural vaporization of LNG or LNG stored in the LNG storage tanks (T1, T2, T3, T4) to the main engine and the power generation engine to be used as fuel; the reliquefaction unit is used for recycling the evaporated gas into the LNG storage tanks (T1, T2, T3 and T4) after reliquefaction; and a gas treatment unit (100, 200) for treating the evaporated gas or the gas discharged from the engine.
In addition, a plurality of LNG storage tanks (T1, T2, T3, T4) may be installed, and in this embodiment, as shown in fig. 1 to 5, a ship having four LNG storage tanks (T1, T2, T3, T4) is shown as an example. As described above, in the present embodiment, four LNG storage tanks (T1, T2, T3, and T4) are described as an example, but the present invention is not limited thereto. In the present embodiment, LNG tanks mounted on the bow to stern are referred to as a first tank (T1), a second tank (T2), a third tank (T3), and a fourth tank (T4) in this order.
The manifolds are provided with a liquid manifold for liquid fluid flow and a gas manifold for gaseous fluid flow, respectively, but only the liquid manifold (L) required for explaining the present embodiment is shown in fig. 1 to 5.
The fluid delivery tube includes: a Liquid Line (LL) arranged to transfer liquid LNG between the manifold (L) and the LNG storage tanks (T1, T2, T3, T4); a Stripping Line (SL); and a Gas Line (GL) for conveying gaseous natural gas.
The Liquid Line (LL) and the Stripping Line (SL) are connected by a manifold (L) and a liquid crossover Line (LC).
LNG may be transferred through the Liquid Line (LL) when LNG is offloaded from the LNG storage tanks (T1, T2, T3, T4) through the manifold (L) and when LNG is loaded to the LNG storage tanks (T1, T2, T3, T4) through the manifold (L).
In addition, LNG may flow along the Stripping Line (SL) when LNG is transferred for injection of LNG to the LNG storage tanks (T1, T2, T3, T4) through the manifold (L) and for stripping LNG in the LNG storage tanks (T1, T2, T3, T4).
The ship of the present embodiment further includes a line branching from the Liquid Line (LL) toward each of the LNG storage tanks (T1, T2, T3, and T4). More specifically, it comprises: a first liquid line (LL 1) branching from the Liquid Line (LL) to a first storage tank (T1); a second liquid line (LL 2) branching from the Liquid Line (LL) to a second storage tank (T2); a third liquid line (LL 3) branching from the Liquid Line (LL) to a third storage tank (T3); and a fourth liquid line (LL 4) branching from the Liquid Line (LL) to a fourth storage tank (T4).
The first to fourth liquid lines (LL 1, LL2, LL3 and LL 4) extend to the inner bottoms of the LNG storage tanks (T1, T2, T3 and T4), respectively.
Furthermore, a line branching from the Stripping Line (SL) toward each LNG storage tank (T1, T2, T3, and T4) is also included. More specifically, it comprises: a first stripping line (SL 1) branching from the Stripping Line (SL) to a first storage tank (T1); a second stripping line (SL 2) branching from the Stripping Line (SL) to a second storage tank (T2); a third stripping line (SL 3) branching from the Stripping Line (SL) to a third storage tank (T3); and a fourth stripping line (SL 4) branching from the Stripping Line (SL) to a fourth storage tank (T4).
The first to fourth stripping lines (SL 1, SL2, SL3, and SL 4) are connected through liquid domes or gas domes of LNG storage tanks (T1, T2, T3, and T4), respectively, and are connected to nozzles installed at the top of the tanks. That is, LNG transferred to the LNG storage tanks (T1, T2, T3, and T4) through the first to fourth stripping lines (SL 1, SL2, SL3, and SL 4) is spray-supplied from the top of the tanks toward the bottom.
In addition, the lengths of the first to fourth stripping lines (SL 1, SL2, SL3, and SL 4) may further extend to the inner bottoms of the LNG storage tanks (T1, T2, T3, and T4), respectively.
The Gas Line (GL) of the present embodiment connects the boil-off gas treatment unit and the LNG storage tanks (T1, T2, T3, T4), and although fig. 1 to 5 show only the Gas Line (GL) through which the boil-off gas discharged from the LNG storage tanks (T1, T2, T3, T4) flows, a boil-off gas line may be further included to flow the gaseous natural gas between the LNG storage tanks (T1, T2, T3, T4) and the manifold and the boil-off gas treatment unit.
The Gas Line (GL) includes a branch line connected from the gas dome of each LNG storage tank (T1, T2, T3 and T4) to the boil-off gas treatment unit. More specifically, it comprises: a first gas line (GL 1) branching from the Gas Line (GL) to the first storage tank (T1); a second gas line (GL 2) branching from the Gas Line (GL) to a second storage tank (T2); a third gas line (GL 3) branching from the Gas Line (GL) to a third storage tank (T3); and a fourth gas line (GL 4) branching from the Gas Line (GL) to the fourth storage tank (T4).
In addition, although not shown in the drawings, the boil-off gas treatment unit may include: a boil-off gas fuel supply unit for compressing a boil-off gas generated in the LNG storage tanks (T1, T2, T3, and T4) to supply the boil-off gas as engine fuel; a reliquefaction unit for reliquefying the boil-off gas and then recovering the liquefied boil-off gas to the LNG storage tanks (T1, T2, T3, T4); and a gas combustion unit for burning and treating the evaporated gas.
In addition, the boil-off gas treatment unit further includes: a compressor (100) that pressurizes boil-off gas generated in the LNG storage tanks (T1, T2, T3, and T4); and a heater (200) for heating the evaporation gas compressed by the compressor (100).
In addition, although not shown in the drawings, the first to fourth gas lines (GL 1, GL2, GL3, GL 4) may be connected to an exhaust tower (VM) that discharges the evaporation gas into the atmosphere, respectively. That is, if necessary, the boil-off gas may be discharged through a vent tower (VM) for treatment.
In addition, the liquefied gas supply system according to the present embodiment further includes a second connection line (CL 2) for connecting the Liquid Line (LL) and the degassing tower (VM).
The second connection line (CL 2) of the present embodiment connects the Liquid Line (LL) and the vent column (VM). In addition, the second connecting line (CL 2) may also connect the Liquid Line (LL) and the gas dome of the first storage tank (T1).
The above-described configuration is generally a basic configuration to be installed in an LNG ship, and the present embodiment provides a method that can treat boil-off gas generated when LNG is supplied from an LNG-filling ship to the ship of the present embodiment on the ship without being returned to the LNG-filling ship by using the above-described basic configuration.
In the embodiment described below, LNG is supplied to the fourth tank (T4), but the present invention is not limited thereto, and even if the description thereof is omitted, it is understood that LNG may be supplied to LNG storage tanks (T1, T2, T3) which are other LNG objects to be cooled or supplied, and that the same applies to the LNG storage tanks by changing only the LNG objects.
According to the present embodiment, it is possible to simultaneously perform the cooling process and the replacement process of a plurality of LNG storage tanks (T1, T2, T3, T4), and simultaneously perform the supply process and the replacement process.
For example, any one of the tanks for which the replacement process has been completed is cooled, and the evaporated gas generated when the tank is cooled is heated and supplied as a replacement gas to the other tank.
In addition, LNG may be supplied to an already cooled tank, and boil-off gas generated when LNG is supplied may be heated and supplied as a replacement gas for another tank.
First, an initial cooling method of the LNG storage tanks (T1, T2, T3, T4) will be described with reference to fig. 2 and 3, and in the present embodiment, a method of cooling will be described with the fourth storage tank (T4) as a storage tank to be cooled as a representative example.
The ship according to the present embodiment is connected to an LNG refueling ship through a manifold (L). LNG for cooling the fourth tank (T4) is injected and supplied from the LNG-filling ship to the fourth tank (T4), the LNG being injected and supplied along the liquid crossover Line (LC), the Stripping Line (SL) and the fourth stripping line (SL 4).
When LNG for cooling is injected and supplied to the fourth tank (T4), a large amount of boil-off gas is generated in the fourth tank (T4). At this time, the evaporation gas generated in the fourth tank (T4) is supplied to the third tank (T3), which is the replacement process object, through the fourth gas line (GL 4), the Gas Line (GL), and the third gas line (GL 3) as a gas for replacement. Thus, the replacement process of the third tank (T3) can be performed while the cooling process of the fourth tank (T4) is performed.
In addition, the evaporation gas discharged from the fourth storage tank (T4) may be compressed in the compressor (100), heated in the heater (200), and then supplied as a replacement gas to the third storage tank (T3).
For example, for 173,400M3 LNG carriers, the replacement process for each storage tank takes approximately 6 hours, using about 6-8MT/hr of gas. According to the present embodiment, the boil-off gas discharged from the cooling tank for performing the cooling process is heated by using the heater (200), which is a basic device mounted on the ship, and supplied as the replacement gas to the replacement tank for performing the replacement process.
That is, according to the embodiment of the present invention, the replacement process of the replacement tank (T3) adjacent to the cooling tank (T4) that performs cooling can be performed while cooling any one of the cooling tanks (T4).
As described above, the inert gas is filled thereto due to the drying and safety problems of the empty tank, and as described above, when the replacement gas is supplied to the third storage tank (T3), the inert gas filled in the third storage tank (T3) is pushed out and discharged through the third liquid line (LL 3).
According to the present embodiment, when the replacement process of the third tank (T3) is performed while the cooling process of the fourth tank (T4) is performed, the inert gas is discharged from the third tank (T3) through the third liquid line (LL 3).
The inert gas discharged along the third liquid line (LL 3) is conveyed to the exhaust tower (VM) along the Liquid Line (LL) and the second connection line (CL 2).
That is, LNG for cooling is supplied to the fourth storage tank (T4) using the Liquid Line (LL), and at the same time, inert gas is delivered to the vent tower (VM) from the liquid line.
On the other hand, as shown in fig. 2 and 3, the above basic configuration and additional configuration may be used, so that boil-off gas generated when LNG is supplied from the LNG carrier to the ship is handled in the ship without being returned to the LNG carrier.
According to the present embodiment, as an additional configuration, it may further include: a first connection line (CL 1) that connects a liquid branch line (LL 1, LL2, LL3, LL 4) branched from the liquid line LL and connected to each of the storage tanks (T1, T2, T3, T4) to bypass an Isolation Valve (IV) (described later); an Isolation Valve (IV) provided in the stern-side Liquid Line (LL) at the position where the first connecting line (CL 1) is connected to the Liquid Line (LL) to shut off the flow of the front end and the rear end.
When further comprising the first connection line (CL 1), the inert gas discharged along the third liquid line (LL 3) may be transferred to the exhaust tower (VM) along the first connection line (CL 1), the Liquid Line (LL) and the second connection line (CL 2).
The first connection line (CL 1) and the second connection line (CL 2) may not be connected to the Liquid Line (LL), but may be directly connected from the third liquid line (LL 3) to the vent tower (VM). At this time, the total length of the connecting lines (CL 1 and CL 2) was 50m at the maximum as a 200A-specification pipe line, taking 173K class ships as a standard.
For example, the first connection line (CL 1) connects the rear end of the Isolation Valve (IV) provided in the third liquid line (LL 3) and the Liquid Line (LL).
An Isolation Valve (IV) is installed between the point where the liquid crossover Line (LC) intersects the Liquid Line (LL) and the point where the LNG storage tank branches from the intersection point to the first crossover (T4).
In addition, an Isolation Valve (IV) is installed between a point where the first connection line (CL 1) is connected to the Liquid Line (LL) and a point where it is connected to the liquid crossover Line (LC).
That is, LNG for cooling may be supplied to the fourth storage tank (T4) using the Liquid Line (LL), and at the same time, inert gas may be transferred to the degassing tower (VM) through the Liquid Line (LL). At this time, the Isolation Valve (IV) may be closed, and the front end and the rear end of the Liquid Line (LL) may be shut off with respect to the Isolation Valve (IV).
Meanwhile, as shown in fig. 3, the Isolation Valve (IV) may be further provided at a place where the liquid crossing Line (LC) and the Liquid Line (LL) are connected, and in this case, the Isolation Valve (IV) may be provided as a three-way valve.
When the Isolation Valve (IV) is provided as a three-way valve as shown in fig. 3, as described above, the fourth tank (T4) to be cooled is cooled, and the replacement process of the third tank (T3) to be replaced is performed, the side of the Isolation Valve (IV) which is directed to the third tank (T3) to communicate with the vent tower (VM) is opened, and the side which is communicated with the liquid crossover Line (LC) may be closed to prevent mutual communication.
In this way, when the replacement process of the third tank (T3) is performed while the fourth tank (T4) is being cooled, the Isolation Valve (IV) can be controlled to communicate the liquid crossover Line (LC) with the Stripping Line (SL) and to not communicate the liquid crossover Line (LC) with the Liquid Line (LL).
Next, with reference to fig. 4 and 5, a method of supplying LNG to a ship according to the present embodiment, in which a method of supplying LNG to a fourth storage tank (T4) will be described as a representative example, will be described.
For example, after the replacement process and the cooling process are completed, LNG is supplied to any one of the storage tanks to be supplied, which is ready to receive LNG, and boil-off gas generated in the storage tank to be supplied during LNG supply is heated and then supplied as a replacement gas to the other storage tank to be replaced.
The amount of boil-off gas generated when the cooling process of the fourth tank (T4) is performed is about 120 tons/hour, which is sufficient to complete the replacement process of the third tank (T3). In addition, after the replacement process of the third tank (T3) is completed, the amount is also sufficient to perform a part of the replacement process of another tank, such as the second tank (T2).
Therefore, the embodiment of the present invention described later will be described taking, as an example, a replacement process for the second tank (T2) by using the boil-off gas generated in the fourth tank (T4) when LNG is supplied to the fourth tank (T4) after the cooling process is completed.
That is, substantially as described above, when the cooling process of the fourth tank (T4) is performed, the replacement process of the third tank (T3) which is the immediately adjacent tank is also completed. Thereafter, when LNG is supplied to the fourth tank (T4) that completes the cooling process, the boil-off gas generated at the fourth tank (T4) may be used to perform a replacement process of the second tank (T2) and/or the first tank (T1), that is, it may be used to perform a replacement process of another tank.
In the present embodiment, the Isolation Valve (IV) functions to shut off the flow direction of LNG and the flow direction of replacement gas from each other in order to supply the vaporization gas discharged from the fourth tank (T4) as the replacement gas to the second tank (T2) or the first tank T1 when LNG is supplied to the fourth tank (T4) where cooling is completed.
The ship according to the present embodiment is connected to an LNG refueling ship through a manifold (L). LNG for commissioning supplied from the LNG refueling ship to the fourth storage tank (T4) is supplied to the fourth storage tank (T4) along the liquid crossover Line (LC), the Liquid Line (LL), and the fourth liquid line (LL 4).
When LNG is supplied to the fourth tank (T4), a large amount of boil-off gas is generated in the fourth tank (T4). At this time, the boil-off gas generated in the fourth tank (T4) is supplied to the second tank (T2) through the fourth gas line (GL 4), the Gas Line (GL) and the second gas line (GL 2) to be used as the replacement gas, whereby the replacement process of the second tank (T2) can be performed while the LNG process is supplied to the fourth tank (T4).
In addition, the evaporation gas discharged from the fourth storage tank (T4) may be compressed in the compressor (100), heated in the heater (200), and then supplied as the replacement gas of the second storage tank (T2).
That is, according to an embodiment of the present invention, while LNG is supplied to any one of the storage tanks (T4) to be supplied, a replacement process of another storage tank (T2) to be replaced may also be performed, the storage tank (T2) being a storage tank to be replaced other than the storage tank (T3) completing the replacement process while a cooling process is performed before the supply process of the storage tank (T4) to be supplied and the storage tank (T4) to be supplied.
As described above, the empty tank is filled with the inert gas due to the drying and safety problems of the empty tank, and when the replacement gas is supplied to the second storage tank (T2) as described above, the internally filled inert gas is pushed out and discharged through the liquid line (LL 2).
According to the present embodiment, when the replacement process of the second tank (T2) is performed while LNG is supplied to the fourth tank (T4), inert gas is discharged from the second tank (T2) through the second liquid line (LL 2).
The inert gas discharged along the second liquid line (LL 2) is conveyed to the exhaust tower (VM) along the Liquid Line (LL) and the second connection line (CL 2).
That is, LNG is supplied to a fourth tank (T4) which is a stern-side tank by a Liquid Line (LL), and inert gas is supplied to a vent tower (VM) through the Liquid Line (LL) connected to the bow side with reference to an Isolation Valve (IV).
At this time, the Isolation Valve (IV) is in a closed state to shut off the flow of the Liquid Line (LL) on the stern side and the liquid line LL on the bow side based on the Isolation Valve (IV).
In addition, as shown in fig. 5, the Isolation Valve (IV) may also be provided at a place where the liquid crossover Line (LC) and the Liquid Line (LL) are connected. In this case, the Isolation Valve (IV) may be provided as a three-way valve.
As shown in fig. 5, when the Isolation Valve (IV) is provided as a three-way valve, LNG is supplied to the tank to be supplied, i.e., the fourth tank (T4), as described above, and when the replacement process of the tank to be replaced, i.e., the second tank (T2), is performed, the Isolation Valve (IV) is controlled so that the liquid crossover Line (LC) and a part of the Liquid Line (LL) are communicated, and the liquid crossover Line (LC) and the Stripping Line (SL) are not communicated.
However, under the control of the Isolation Valve (IV), the liquid crossover Line (LC) and the Liquid Line (LL) are only in communication with the fourth tank (T4), which is the tank to be supplied, and are not in communication with the second tank (T2), which is the tank to be replaced.
In other words, when the replacement process of the second tank (T2) is performed while LNG is supplied to the fourth tank (T4), although the supply of LNG to the fourth tank (T4) and the discharge of inert gas from the second tank (T2) are both completed through the Liquid Line (LL), the Isolation Valve (IV) cuts off the path of LNG flowing from the manifold (L) to the fourth tank (T4) and the path of inert gas flowing from the second tank (T2) to the vent tower (VM) with reference to the Isolation Valve (IV) to be isolated from each other.
Next, a ship liquefied gas fuel supply system and method according to an embodiment of the present invention will be described with reference to fig. 6 to 10.
A ship according to an embodiment of the present invention includes: two or more LNG fuel tanks (T1 and T2); a manifold (L) for connecting a ship or a receiving station (e.g., LNG refueling ship) that supplies LNG to LNG fuel tanks (T1 and T2); and a fluid transfer pipe for connecting the LNG fuel tanks (T1, T2) with the manifold (L).
The fluid delivery tube includes: a liquefied gas line that supplies LNG from the LNG supply vessel to any one of two or more LNG fuel tanks (T1 and T2); a gas discharge line for discharging boil-off gas generated by supplying LNG to any one of the LNG fuel tanks; and a gas supply line for supplying boil-off gas to one or more other LNG storage tanks.
In the present embodiment described later, the liquefied gas line may be referred to as a Liquid Line (LL), liquid branch lines (LL 1, LL 2), a Stripping Line (SL), and stripping branch lines (SL 1, SL 2).
In addition, the gas discharge line may refer to the Gas Line (GL), the gas branch lines (GL 1 and GL 2), and the Connection Line (CL), or the gas discharge line may be the liquid line LL and the liquid branch lines (LL 1 and LL 2) while flowing along the Liquid Line (LL) and the liquid branch lines (LL 1 and LL 2).
In addition, the gas supply line may refer to a Gas Line (GL) and gas branch lines (GL 1 and GL 2).
In the ship of the present embodiment, a plurality of LNG storage tanks may be provided, and the plurality of LNG storage tanks may include two or more LNG fuel tanks (T1 and T2), and may further include one or more LNG cargo tanks if the ship is an LNG carrier.
In the present embodiment, the ship is connected to an LNG refueling ship, and receives LNG from the LNG refueling ship to LNG fuel tanks (T1 and T2) through a manifold, that is, a method of treating boil-off gas when LNG is to be filled is described as an example.
In addition, in one embodiment of the present invention, the description will be given taking as an example that LNG for initial cooling of an LNG storage tank or for commissioning, or LNG fuel is supplied (filled) from an LNG refueling ship in order to recharge the ship. However, the present invention is not limited thereto, and in an LNG ship provided with two or more LNG tanks, for example, in supplying LNG to an LNG fuel tank of an LNG fuel ship or supplying LNG to an LNG fuel tank or the like, it may be applied in various ways in any case.
In addition, although not shown in the drawings, the ship according to the present embodiment may include: a main engine for generating propulsion energy using LNG stored in LNG fuel tanks (T1 and T2) as fuel; a power generation engine for generating electric power using LNG stored in LNG fuel tanks (T1 and T2) as fuel; a fuel supply unit for supplying vaporized gas generated by natural vaporization of LNG or LNG stored in the LNG fuel tanks (T1 and T2) to the main engine and the power generation engine to be used as fuel; the re-liquefying unit is used for re-liquefying the evaporated gas and then recycling the evaporated gas into the LNG fuel tanks (T1 and T2); and a gas treatment unit (100, 200) for treating the evaporated gas or the gas discharged from the engine.
In addition, the LNG fuel tanks (TI and T2) may be provided in two or more, and in the present embodiment, as shown in fig. 6 to 10, a ship provided with two LNG fuel tanks (T1 and T2) is shown as an example.
As described above, in the present embodiment, the two LNG fuel tanks (T1 and T2) are provided as an example, but the present invention is not limited thereto. In the present embodiment, LNG fuel tanks mounted on the bow to stern are referred to as a first fuel tank (T1) and a second fuel tank (T2) in this order.
The manifolds include a liquid manifold for flowing a liquid fluid and a gas manifold for flowing a gaseous fluid, respectively, but only a liquid manifold (L) necessary for explaining the present embodiment is shown in fig. 6 to 10.
The fluid delivery tube includes: a Liquid Line (LL) provided to transfer liquid LNG between the manifold (L) and the LNG fuel tanks (T1, T2); a Stripping Line (SL); and a Gas Line (GL) for conveying gaseous natural gas.
The Liquid Line (LL) and the Stripping Line (SL) are connected to the liquid crossover Line (LC) via a manifold (L).
LNG may be transferred through the Liquid Line (LL) when LNG is offloaded from the LNG fuel tanks (T1 and T2) through the manifold (L) and when LNG is supplied to the LNG fuel tanks (T1 and T2) through the manifold (L).
In addition, LNG may flow along the Stripping Line (SL) when LNG is transferred for injection of LNG to the fuel tanks (T1 and T2) through the manifold (L) and for stripping of LNG in the LNG fuel tanks (T1 and T2).
The ship of the present embodiment further includes a liquid branch line branching from the Liquid Line (LL) toward each of the LNG fuel tanks (T1 and T2). More specifically, it comprises: a first liquid line (LL 1) branching from the Liquid Line (LL) to a first fuel tank (T1); a second liquid line (LL 2) branching from the Liquid Line (LL) to a second fuel tank (T2).
The first to second liquid lines (LL 1 and LL 2) may extend to the inner bottom surfaces of the LNG fuel tanks (T1 and T2), respectively.
In addition, a stripping branch line branching from the Stripping Line (SL) toward each LNG fuel tank (T1 and T2) is also included. More specifically, it comprises: a first stripping line (SL 1) branching from the Stripping Line (SL) to a first fuel tank (T1); a second stripping line (SL 2) branching from the Stripping Line (SL) to a second fuel tank (T2).
The first and second stripping lines (SL 1 and SL 2) are connected by liquid or gas domes of LNG fuel tanks (T1 and T2), respectively, and are connected to nozzles mounted at the top of the tanks.
That is, LNG transferred to the LNG fuel tanks (T1 and T2) through the first to second stripping lines (SL 1) to (SL 2) can be injected and supplied from the tank top to the bottom thereof.
In addition, the lengths of the first and second stripping lines (SL 1 and SL 2) may further extend to the inner bottoms of the LNG fuel tanks (T1 and T2), respectively.
The Gas Line (GL) of the present embodiment connects the boil-off gas treatment unit and the LNG fuel tanks (T1 and T2), and although fig. 6 to 10 show only the Gas Line (GL) through which the boil-off gas discharged from the LNG fuel tanks (T1 and T2) flows, a steam line may be further included so that the gaseous natural gas flows between the LNG fuel tanks (T1, T2) and the manifold and the boil-off gas treatment unit.
The Gas Line (GL) includes a gas branch line connected from a gas dome in each LNG fuel tank (T1 and T2) to the boil-off gas treatment unit. More specifically, it comprises: a first gas line GL1 branching from the gas line GL to a first fuel tank T1; and a second gas line (GL 2) branching from the Gas Line (GL) to the second fuel tank (T2).
In addition, although not shown in the drawings, the boil-off gas treatment unit may include: a boil-off gas fuel supply unit for compressing a boil-off gas generated in the LNG fuel tanks (T1 and T2) to supply the boil-off gas as an engine fuel; a reliquefaction unit for reliquefying the boil-off gas and recycling the liquefied boil-off gas to the LNG fuel tanks (T1 and T2); and a gas combustion unit for burning and treating the evaporated gas.
In addition, the boil-off gas treatment unit includes: a compressor (100) for pressurizing boil-off gas generated in the LNG fuel tanks (T1 and T2); and a heater (200) for heating the evaporation gas compressed by the compressor (100).
In addition, although not shown in the drawings, the first to second gas lines (GL 1 to GL 2) may be connected to an exhaust tower (VM) that discharges the evaporation gas into the atmosphere, respectively. That is, if necessary, the process may be performed by discharging the boil-off gas through a vent tower (VM).
In addition, the liquefied gas fuel supply system of the ship according to the present embodiment further includes a Connection Line (CL) for connecting the Liquid Line (LL) and the exhaust tower (VM).
The Connection Line (CL) of the present embodiment connects the Liquid Line (LL) and the vent column (VM). The Connection Line (CL) may also connect the Liquid Line (LL) and the gas dome of the first fuel tank (T1).
The above-described configuration is generally a basic configuration to be mounted on an LNG ship, and the present embodiment provides a method by which boil-off gas generated when LNG is supplied from an LNG-filling ship to the ship of the present embodiment can be handled on the ship without being returned to the LNG-filling ship, using the above-described basic configuration.
In the embodiment described below, LNG is supplied to the first fuel tank (T1), but the present invention is not limited thereto, and although the description thereof is omitted, it is understood that the present invention is equally applicable to the case where LNG is supplied to other LNG fuel tanks (T1 and T2) to be cooled or to be supplied with LNG, and the present invention is also applicable to the case where only the LNG is converted.
According to the present embodiment, the cooling process and the replacement process of two or more LNG fuel tanks (T1 and T2) and the supply process and the replacement process can be simultaneously performed.
For example, any one of the fuel tanks (T1) for which the replacement process is completed is cooled, and the evaporated gas generated when the fuel tank is cooled is heated and supplied as a replacement gas to the other fuel tank (T2).
Further, LNG may be supplied to the fuel tank (T1) where cooling is completed, and boil-off gas generated when LNG is supplied may be heated and then supplied as a replacement gas for the other fuel tank (T2).
A method of cooling the LNG fuel tanks (T1 and T2) will be described with reference to fig. 7 and 8, and in the present embodiment, as a representative example, a method of cooling will be described with the first fuel tank (T1) as the fuel tank to be cooled.
The ship according to the present embodiment is connected to an LNG refueling ship through a manifold (L). LNG for cooling is spray-supplied from the LNG-filling ship to the first fuel tank (T1), which LNG is spray-supplied along the liquid crossover Line (LC), the Stripping Line (SL) and the first stripping line (SL 1).
When LNG injection for cooling is supplied to the first fuel tank (T1), a large amount of boil-off gas is generated in the first fuel tank (T1). At this time, the boil-off gas generated in the first fuel tank (T1) is supplied to the second fuel tank (T2) to be replaced as a gas for replacement through the first gas line (GL 1), the Gas Line (GL), and the second gas line (GL 2). Thus, the process of replacing the second fuel tank (T2) can be performed simultaneously with the cooling process of the first fuel tank (T1).
In addition, the boil-off gas discharged from the first fuel tank (T1) may be compressed in the compressor (100), heated in the heater (200), and then supplied as a displacement gas to the second fuel tank (T2).
For example, in the case of 173,400M3 LNG carriers, the replacement process for each fuel tank takes about 6 hours, with about 6-8MT/hr of gas used. According to the present embodiment, the boil-off gas discharged from the first fuel tank (T1) performing the cooling process is heated by using the heater (200) which is a basic constitution mounted on the ship, and is supplied as the replacement gas to the second fuel tank (T2) to be subjected to the replacement process.
That is, according to the embodiment of the present invention, the replacement process of the fuel tank (T2) to be replaced adjacent to the fuel tank (T1) to be cooled can be performed while cooling any one of the fuel tanks (T1) to be cooled.
As described above, the inert gas is filled into the empty tank due to drying and safety problems, and as described above, when the replacement gas is supplied to the second fuel tank (T2), the inert gas filled in the second fuel tank (T2) is pushed out and discharged through the second liquid line (LL 2).
According to the present embodiment, when the replacement process of the second fuel tank (T2) is performed simultaneously with the cooling process of the first fuel tank (T1), the inert gas is discharged from the second fuel tank (T2) through the second liquid line (LL 2).
The inert gas discharged along the second liquid line (LL 2) is conveyed to the degassing tower (VM) along the Liquid Line (LL) and the Connection Line (CL).
That is, LNG for cooling is supplied to the first fuel tank (T1) by the Liquid Line (LL), and at the same time, inert gas discharged from the second fuel tank (T2) is sent to the exhaust tower (VM) by the Liquid Line (LL).
As shown in fig. 7 and 8, the above basic configuration and additional configuration may be used to treat boil-off gas generated when LNG is supplied from the LNG carrier to the ship, without being returned to the LNG carrier, in the ship.
According to the present embodiment, as an additional constitution, an Isolation Valve (IV) installed in the Liquid Line (LL) to shut off the flow of the front end and the rear end may be further included.
The Connection Line (CL) may not be connected to the Liquid Line (LL), but may be directly connected from the liquid branch line to the vent tower (VM). At this time, the total length of the Connecting Line (CL) was 50m at the maximum as a 200A-specification pipeline, taking 173K class ships as a standard.
The Isolation Valve (IV) of the present embodiment is installed at a place where the liquid intersecting Line (LC) intersects the Liquid Line (LL) or between the place where the liquid intersecting line intersects with any one of the liquid branch lines branches to any one of the LNG fuel tanks (T1, T2).
In the drawings of the present embodiment, it is shown as an example that the Isolation Valve (IV) is provided between a place where the liquid intersecting Line (LC) and the Liquid Line (LL) intersect and a place where the second liquid line (LL 2) branches from the Liquid Line (LL), or at a place where the liquid intersecting Line (LC) and the Liquid Line (LL) intersect with the Liquid Line (LL).
That is, LNG may be supplied to the first fuel tank (T1) using the Liquid Line (LL) or the Stripping Line (SL), and at the same time, inert gas is transferred to the vent tower (VM) through the Liquid Line (LL). At this time, the Isolation Valve (IV) may be closed, and the flow of the front end and the rear end of the Liquid Line (LL) may be shut off based on the Isolation Valve (IV) so that the inert gas does not flow to the first fuel tank (T1).
Meanwhile, as shown in fig. 8, when the Isolation Valve (IV) is provided at a place where the liquid crossover Line (LC) and the Liquid Line (LL) are connected, the Isolation Valve (IV) may be provided as a three-way valve.
As shown in fig. 8, when the Isolation Valve (IV) is provided as a three-way valve, as described above, the first fuel tank (T1) to be cooled is cooled, and the replacement process is performed on the second fuel tank (T2) to be replaced, the Isolation Valve (IV) is opened toward the side of the second fuel tank (T2) communicating with the exhaust tower (VM), and the side communicating with the liquid crossover Line (LC) may be closed to prevent mutual communication.
As described above, when the cooling process of the first fuel tank (T1) and the replacement process of the second fuel tank (T2) are simultaneously performed, the Isolation Valve (IV) can be controlled to communicate the liquid crossover Line (LC) and the Stripping Line (SL) so that the liquid crossover Line (LC) and the Liquid Line (LL) are not communicated.
Next, with reference to fig. 9 and 10, a method of supplying LNG to the ship of the present embodiment will be described, in which a method of supplying LNG to the first fuel tank (T1) will be described as a representative example.
For example, after the replacement process and the cooling process are completed, LNG may be supplied to any one of the fuel tanks that is ready to receive LNG, and boil-off gas generated in the fuel tank to be supplied during the supply of LNG may be heated and then supplied as a replacement gas to the other fuel tank to be replaced.
The amount of boil-off gas generated when the above-described cooling process of the first fuel tank (T1) is carried out is about 120 tons/hour, which is sufficient to complete the replacement process of the second fuel tank (T2). In addition, after the replacement process of the second fuel tank (T2) is completed, a replacement process of another fuel tank or cargo tank to be replaced may be performed.
The embodiment of the present invention described below is described taking as an example a replacement process for the second fuel tank (T2) using the boil-off gas generated in the first fuel tank (T1) when LNG is supplied to the first fuel tank (T1), but substantially as described above, when the cooling process for the first fuel tank (T1) is performed, the boil-off gas generated in the first fuel tank (T1) can be used to perform a replacement process for other fuel tanks or LNG tanks other than the fuel tank that has been replaced when the first fuel tank (T1) is cooled.
In the present embodiment, the Isolation Valve (IV) functions to shut off the direction of LNG flow and the direction of replacement gas flow from each other in order to transfer the boil-off gas discharged from the first fuel tank (T1) as the replacement gas to the second fuel tank (T2) or other LNG storage tank when LNG is supplied to the cooled first fuel tank (T1).
The ship according to the present embodiment is connected to an LNG refueling ship through a manifold (L). LNG fuel to be supplied from an LNG filling ship to a first fuel tank (T1) is supplied to the first fuel tank (T1) along a liquid crossover Line (LC), a Liquid Line (LL), and a first liquid line (LL 1).
When LNG is supplied to the first fuel tank (T1), a large amount of boil-off gas is generated in the first fuel tank (T1). At this time, the boil-off gas generated in the first fuel tank (T1) is supplied to the second fuel tank (T2) through the first gas line GL1, the Gas Line (GL) and the second gas line (GL 2) to be used as the replacement gas, whereby the replacement process of the second fuel tank (T2) can be performed while the process of supplying LNG to the first fuel tank (T1) is performed.
The evaporated gas discharged from the first fuel tank (T1) can be compressed in the compressor (100), heated by the heater (200), and then supplied as a replacement gas for the second fuel tank (T2).
That is, according to an embodiment of the present invention, a replacement process of another fuel tank (T2) to be replaced may be performed while LNG is supplied to any one of the fuel tanks (T1) to be supplied, the fuel tank (T2) being another fuel tank to be replaced other than the fuel tank that completes the replacement process when the fuel tank (T1) to be supplied and the supply process of the first fuel tank (T1) to be supplied are cooled before.
As described above, when the empty tank is filled with the inert gas due to the drying of the empty pipe and the safety problem, and the replacement gas is supplied to the second fuel tank (T2) as described above, the internally filled inert gas is pushed out and discharged through the liquid line (LL 2).
According to the present embodiment, when the replacement process of the second fuel tank (T2) is performed while LNG is supplied to the first fuel tank (T1), inert gas is discharged from the second fuel tank (T2) through the second liquid line (LL 2).
The inert gas discharged along the second liquid line (LL 2) is conveyed to the degassing tower (VM) along the Liquid Line (LL) and the Connection Line (CL).
For example, LNG is supplied to a first fuel tank (T1) which is a fuel tank on the stern side by a Liquid Line (LL), and inert gas is supplied to an exhaust tower (VM) through the Liquid Line (LL) connected to the bow side with reference to an Isolation Valve (IV).
At this time, the Isolation Valve (IV) is in a closed state to shut off the flow of the Liquid Line (LL) on the stern side and the Liquid Line (LL) on the bow side based on the Isolation Valve (IV).
In addition, as shown in fig. 10, the Isolation Valve (IV) may be provided at a place where the liquid crossing Line (LC) and the Liquid Line (LL) are connected, and in this case, the Isolation Valve (IV) may be provided as a three-way valve.
Referring to fig. 10, when the Isolation Valve (IV) is provided as a three-way valve, LNG is supplied to the first fuel tank (T1), which is the fuel tank to be supplied, and the replacement process of the second fuel tank (T2), which is the fuel tank to be replaced, is performed as described above, the Isolation Valve (IV) is controlled so that the liquid crossover Line (LC) communicates with the Liquid Line (LL) on the side where the first liquid line (LL 1) branches, and does not communicate with the Liquid Line (LL) on the side where the second liquid line (LL 2) branches.
However, under the control of the Isolation Valve (IV), the liquid crossover Line (LC) and the Liquid Line (LL) communicate only with the side of the first fuel tank (T1) which is the fuel tank to be supplied, and not with the side of the second fuel tank (T2) which is the fuel tank to be replaced.
In this way, when the replacement process of the second fuel tank (T2) is performed while LNG is supplied to the first fuel tank (T1), although the supply of LNG to the first fuel tank (T1) and the discharge of inert gas from the second fuel tank (T2) are both completed through the Liquid Line (LL), the Isolation Valve (IV) cuts off the path of LNG flowing from the manifold (L) to the first fuel tank (T1) and the path of inert gas flowing from the second fuel tank (T2) to the exhaust tower (VM) with reference to the Isolation Valve (IV) to be isolated from each other.
As described above, the embodiments according to the present invention have been described, and the fact that the present invention may be embodied in other specific forms without departing from the spirit or scope thereof, in addition to the above embodiments, will be apparent to those of ordinary skill in the art. The above-described embodiments are therefore to be considered in all respects as illustrative and not restrictive, and the invention is thus not to be limited to the details given above, but may be modified within the scope and equivalents of the appended claims.
Claims (8)
1. A liquefied gas supply system that supplies liquefied gas from a liquefied gas supply vessel to a vessel including a plurality of liquefied gas storage tanks, comprising:
A liquid line for supplying liquefied gas from the liquefied gas supply vessel to the plurality of liquefied gas storage tanks;
a gas line for discharging the boil-off gas generated in one of the liquefied gas storage tanks;
A first liquid line branching from the liquid line to a first storage tank of the plurality of liquefied gas storage tanks;
a second liquid line branching from the liquid line to a second storage tank of the plurality of liquefied gas storage tanks;
A first gas line branching from the gas line to the first storage tank;
a second gas line branching from the gas line to the second storage tank;
A first connection line branching from the first liquid line on the opposite side of the branching point of the second liquid line based on the branching point of the second liquid line and connected to the second liquid line; and
An isolation valve provided between a branching point of the first connection line and a branching point of the second liquid line of the liquid lines to shut off or open a flow of front and rear ends in the liquid lines;
wherein the liquid line is divided into an upstream portion where a branching point of the second liquid line is located and a downstream portion where a branching point of the first connecting line is located based on the isolation valve, and
Wherein gas is discharged from the second storage tank through the second liquid line, the first connecting line and an upstream portion of the liquid line.
2. The liquefied gas supply system as claimed in claim 1, wherein,
Further comprises:
A heater for heating the boil-off gas exhausted along the first gas line,
Wherein the boil-off gas heated at the heater is supplied to the second storage tank through the second gas line.
3. The liquefied gas supply system as claimed in claim 1, further comprising:
a manifold connecting the liquefied gas supply vessel and the vessel including the plurality of liquefied gas storage tanks,
Wherein the isolation valve is disposed between a point where the manifold and the liquid line intersect and a point where the first connecting line and the liquid line intersect.
4. The liquefied gas supply system as claimed in claim 1, wherein,
Further comprises:
a manifold connecting the liquefied gas supply vessel and the vessel comprising the plurality of liquefied gas storage tanks, wherein the isolation valve is a three-way valve disposed at a point where the manifold and the liquid line intersect.
5. The liquefied gas supply system as claimed in claim 1, further comprising:
An exhaust tower;
A second connecting line connecting the liquid line and the exhaust column,
Wherein the gas discharged from the second storage tank that receives the boil-off gas is an inert gas, the inert gas being delivered from the second storage tank to the degassing tower.
6. A liquefied gas supply method for supplying the liquefied gas from the liquefied gas supply vessel to a vessel including the plurality of liquefied gas storage tanks with the liquefied gas supply system according to claim 1, comprising:
A liquefied gas supply step of supplying the liquefied gas from the liquefied gas supply vessel to the first one of the plurality of liquefied gas storage tanks, wherein the liquefied gas flows through the liquid line at a front end of the isolation valve and the first liquid line branching from the liquid line to the first storage tank;
a boil-off gas discharging step of discharging the boil-off gas from the first storage tank through the gas line and the first gas line branched from the gas line to the first storage tank; and
A replacement gas supply step of discharging and supplying the boil-off gas from the first storage tank of the plurality of liquefied gas storage tanks to the second storage tank, wherein the boil-off gas flows through the second liquid line branched from the liquid line, the liquid line at the rear end of the isolation valve, and the first connection line branched from the liquid line and connected to the second liquid line bypassing the isolation valve,
Wherein the liquid line is divided into the upstream portion where the branching point of the second liquid line is located and the downstream portion where the branching point of the first connecting line is located based on the isolation valve, and
Wherein the gas is discharged from the second storage tank through the second liquid line, the first connecting line, and the upstream portion of the liquid line.
7. The liquefied gas supply method as claimed in claim 6, wherein,
Heating the boil-off gas discharged in the boil-off gas discharging step, and supplying the heated boil-off gas to the second storage tank.
8. The liquefied gas supply method as claimed in claim 6, wherein,
Further comprising an inert gas discharging step of discharging inert gas filled in the liquefied gas storage tank receiving the boil-off gas due to receipt of the boil-off gas,
Wherein the inert gas is discharged through a line supplying the liquefied gas to the liquefied gas storage tank,
The step of discharging the inert gas is performed,
Further comprising an isolation step wherein a portion of the liquid line along which the liquefied gas flows to the first storage tank and a portion of the liquid line along which the inert gas flows from the second storage tank are isolated from each other.
Applications Claiming Priority (9)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR10-2019-0174337 | 2019-12-24 | ||
| KR20190174337 | 2019-12-24 | ||
| KR1020200117443A KR20210082056A (en) | 2019-12-24 | 2020-09-14 | Liquefied Gas Supply System and Method |
| KR1020200117444A KR20210082057A (en) | 2019-12-24 | 2020-09-14 | Liquefied Gas Fuel Supply System |
| KR10-2020-0117442 | 2020-09-14 | ||
| KR10-2020-0117443 | 2020-09-14 | ||
| KR10-2020-0117444 | 2020-09-14 | ||
| KR1020200117442A KR20210082055A (en) | 2019-12-24 | 2020-09-14 | Liquefied Gas Supply System and Method |
| PCT/KR2020/017962 WO2021132955A1 (en) | 2019-12-24 | 2020-12-09 | System and method for supplying liquefied gas to ship, and system for supplying liquefied gas fuel to ship |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114929572A CN114929572A (en) | 2022-08-19 |
| CN114929572B true CN114929572B (en) | 2024-10-18 |
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| CN202080086411.0A Active CN114929572B (en) | 2019-12-24 | 2020-12-09 | Ship liquefied gas supply system and method and ship liquefied gas fuel supply system |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JP7445763B2 (en) |
| CN (1) | CN114929572B (en) |
| WO (1) | WO2021132955A1 (en) |
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| FR3117572B1 (en) * | 2020-12-10 | 2023-11-24 | Gaztransport Et Technigaz | GAS TURNING AND GAS TESTING PROCESSES IN A LIQUEFIED GAS STORAGE FACILITY |
| JP7650919B2 (en) | 2023-07-03 | 2025-03-25 | 株式会社三井E&S | Fuel Supply System |
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| KR20130052937A (en) * | 2011-11-14 | 2013-05-23 | 대우조선해양 주식회사 | Liquefied gas carrier having boil-off gas tank |
| KR20170082003A (en) * | 2016-01-05 | 2017-07-13 | 대우조선해양 주식회사 | Fluid transferring line for storage tank of liquid gas |
| KR20180017997A (en) * | 2016-08-12 | 2018-02-21 | 대우조선해양 주식회사 | Lng loading system for lng carrier and method thereof |
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| KR101244460B1 (en) * | 2011-04-11 | 2013-03-18 | 한국과학기술원 | LNG bunkering terminal |
| CN202252837U (en) * | 2011-09-09 | 2012-05-30 | 中国寰球工程公司 | Liquefied natural gas ship unloading and loading system |
| KR101386543B1 (en) * | 2012-10-24 | 2014-04-18 | 대우조선해양 주식회사 | System for treating boil-off gas for a ship |
| KR101519541B1 (en) * | 2013-06-26 | 2015-05-13 | 대우조선해양 주식회사 | BOG Treatment System |
| AU2016372711B2 (en) * | 2015-12-14 | 2019-05-02 | Exxonmobil Upstream Research Company | Method of natural gas liquefaction on LNG carriers storing liquid nitrogen |
| KR101826685B1 (en) * | 2016-04-07 | 2018-02-07 | 대우조선해양 주식회사 | Vaporization Reducing System and Method of Liquid Cargo |
| JP6850305B2 (en) * | 2016-05-04 | 2021-03-31 | イノベイティブ クライオジェニック システムズ， インコーポレイテッド | Equipment for supplying flammable gas to gas consuming parts and for liquefying this flammable gas |
| KR20180003184A (en) * | 2016-06-30 | 2018-01-09 | 삼성중공업 주식회사 | System and method for treating boil-off gas |
| KR102476168B1 (en) * | 2016-12-23 | 2022-12-09 | 쉘 인터내셔날 리써취 마트샤피지 비.브이. | Liquefied gas transport vessel and method of operating the vessel |
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2020
- 2020-12-09 WO PCT/KR2020/017962 patent/WO2021132955A1/en active Application Filing
- 2020-12-09 CN CN202080086411.0A patent/CN114929572B/en active Active
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
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| KR20130052937A (en) * | 2011-11-14 | 2013-05-23 | 대우조선해양 주식회사 | Liquefied gas carrier having boil-off gas tank |
| KR20170082003A (en) * | 2016-01-05 | 2017-07-13 | 대우조선해양 주식회사 | Fluid transferring line for storage tank of liquid gas |
| KR20180017997A (en) * | 2016-08-12 | 2018-02-21 | 대우조선해양 주식회사 | Lng loading system for lng carrier and method thereof |
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| WO2021132955A1 (en) | 2021-07-01 |
| CN114929572A (en) | 2022-08-19 |
| JP2023508857A (en) | 2023-03-06 |
| JP7445763B2 (en) | 2024-03-07 |
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Address after: 3370 Judi Road, Juji City, gyeongshan South Road, South Korea (zip code: 53302) Applicant after: Hanhua Ocean Co.,Ltd. Address before: 3370 Judi Road, Juji City, gyeongshan South Road, South Korea (zip code: 53302) Applicant before: DAEWOO SHIPBUILDING & MARINE ENGINEERING Co.,Ltd. |
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