Liquefied gas carrier

Abstract

This liquefied gas carrier comprises: a liquefied gas tank for storing liquefied gas; a burner for burning fuel; an inert gas generation device for generating inert gas to be supplied to the liquefied gas tank, the inert gas generation device having a fresh water nozzle for spraying fresh water onto combustion exhaust gas generated by the burner, and a seawater nozzle for spraying seawater onto the combustion exhaust gas after the fresh water is sprayed; an inert-gas-generation-device fresh water tank for storing fresh water to be supplied to the inert gas generation device; a fresh water supply line for supplying fresh water from the inert-gas-generation-device fresh water tank to the inert gas generation device; a seawater supply line for supplying seawater to the inert gas generation device; and a hull in which the liquefied gas tank, the inert gas generation device, the inert-gas-generation-device fresh water tank, the fresh water supply line, and the seawater supply line are mounted.

Description

liquefied gas carrier

[0001] The present disclosure relates to a liquefied gas carrier equipped with liquefied gas tanks.

[0002] Generally, ships enter dry docks once every few years for periodic inspections. When a liquefied gas carrier enters dry dock, the remaining flammable gas in the tank is first replaced with inert gas in order to inspect the liquefied gas tanks. The inert gas in the tank is then replaced with air to create an environment in which workers can enter the tank. After inspection, before loading the liquefied gas tank, the air in the tank is first replaced with inert gas, and the inert gas in the tank is then replaced with vaporized liquefied gas, which is the cargo, before cooling the tank begins. Liquefied gas carriers are equipped with inert gas generators that generate inert gas, and the inert gas generated by the inert gas generator is used in the gas replacement inside the tanks described above.

[0003] Patent Document 1 describes a ship equipped with an inert gas generator, a cargo tank, and a ballast tank, in which inert gas generated by the inert gas generator is stored in a pressurized state in the ballast tank, and the inert gas stored in the ballast tank is used to replace the gas in the cargo tank. Examples of inert gas generators include an apparatus (IGS) that generates inert gas from combustion exhaust gas of a boiler, an apparatus (IGG) that generates inert gas from combustion exhaust gas generated by burning fuel in a dedicated oil burner, and a nitrogen gas generator (NGG) that obtains nitrogen from the atmosphere using electricity.

[0004] JP 2011-178250 A

[0005] Inert gas generators that generate inert gas from flue gas generated by fuel combustion are equipped with scrubbers that clean and cool the flue gas. The scrubber cleans the flue gas by capturing and separating particles in the flue gas in droplets or a liquid film of a cleaning liquid, and cools the flue gas by bringing the flue gas into contact with the cleaning liquid. The scrubbers of inert gas generators installed on ships use seawater, which is abundant around the ship, as the cleaning liquid.

[0006] When seawater is used as a cleaning liquid in a scrubber, the low-temperature seawater evaporates upon contact with the high-temperature combustion exhaust gas, and the salt content of the seawater remains in the inert gas that is generated. When such salt-containing inert gas is used for gas replacement in a liquefied gas tank, the salt from the inert gas adheres to the inner walls of the liquefied gas tank. If salt adheres to the inner walls of the liquefied gas tank, it may cause a decrease in the purity of the cargo newly loaded into that liquefied gas tank.

[0007] The present disclosure has been made in consideration of the above circumstances, and its purpose is to propose a liquefied gas carrier equipped with a liquefied gas tank and an inert gas generator, which replaces the gas inside the liquefied gas tank with inert gas generated by the inert gas generator, and which is equipped with a configuration that suppresses a decrease in the purity of the liquefied gas newly loaded into the liquefied gas tank.

[0008] In order to solve the above problems, a liquefied gas carrier according to one embodiment of the present disclosure comprises: a liquefied gas tank for storing liquefied gas; an inert gas generator having a burner for burning fuel, a fresh water nozzle for spraying fresh water onto combustion exhaust gas generated by the burner, and a seawater nozzle for spraying seawater onto the combustion exhaust gas after the fresh water has been sprayed, and for generating inert gas to be supplied to the liquefied gas tank; a fresh water tank for the inert gas generator for storing fresh water to be supplied to the inert gas generator; a fresh water supply line for supplying fresh water from the fresh water tank for the inert gas generator to the inert gas generator; a seawater supply line for supplying seawater to the inert gas generator; and a hull carrying the liquefied gas tank, the inert gas generator, the fresh water tank for the inert gas generator, the fresh water supply line, and the seawater supply line.

[0009] According to the present disclosure, in a liquefied gas carrier equipped with a liquefied gas tank and an inert gas generator, in which the gas in the liquefied gas tank is replaced with inert gas generated by the inert gas generator, it is possible to suppress a decrease in the purity of the liquefied gas newly loaded into the liquefied gas tank.

[0010] Fig. 1 is a side view showing the overall configuration of a liquefied gas carrier according to an embodiment of the present disclosure. Fig. 2 is a partial plan view of the liquefied gas carrier illustrating the arrangement of a sub-fresh water tank. Fig. 3 is a diagram showing a fresh water flow path system through which fresh water flows. Fig. 4 is a schematic diagram of an inert gas generator.

[0011] <<Overall Structure of Liquefied Gas Carrier 1>> Figure 1 is a side view showing the overall configuration of a liquefied gas carrier 1 according to one embodiment of the present disclosure. The liquefied gas carrier 1 shown in Figure 1 includes a hull 11, and a liquefied gas tank 3, a fresh water tank 4, and an inert gas generator 2 mounted on the hull 11.

[0012] An engine room 14 is provided at the stern of the hull 11, and a cargo space 13 is provided on the bow side of the engine room 14 of the hull 11. In addition to the main engine and auxiliary engines, an inert gas generator 2 is also arranged in the engine room 14. A liquefied gas tank 3 for storing liquefied gas as cargo is arranged in the cargo space 13.

[0013] <<Fresh Water Tanks 4>> Fresh water tanks 4 for storing fresh water are arranged in multiple locations on the hull 11. The multiple fresh water tanks 4 include a main fresh water tank 41 arranged at the stern of the hull 11. The main fresh water tank 41 mainly stores fresh water consumed when the liquefied gas carrier 1 is sailing. For example, the fresh water in the main fresh water tank 41 is used as domestic water or drinking water on the bridge, or for use by the main engine and other equipment in the engine room 14. However, the fresh water in the main fresh water tank 41 may also be used as domestic water or drinking water when the liquefied gas carrier 1 is not sailing, or may be used to supplement part of the fresh water consumed by the inert gas generator 2.

[0014] Because the main fresh water tank 41 is disposed in a limited space below the deck at the stern of the hull 11, the tank size of the main fresh water tank 41 may be limited. With the tank size of the main fresh water tank 41, it may be difficult to supply the entire amount of fresh water sufficient for generating inert gas used to replace the gas in the liquefied gas tank 3 to the inert gas generator 2. Therefore, the multiple fresh water tanks 4 include at least one auxiliary fresh water tank 42 that stores fresh water primarily used in the inert gas generator 2. The auxiliary fresh water tank 42 is a "fresh water tank for the inert gas generator" that stores fresh water to be supplied to the inert gas generator 2. In this embodiment, the auxiliary fresh water tank 42 is disposed in the cargo space 13. FIG. 2 is a partial plan view of the liquefied gas carrier 1 illustrating the arrangement of the auxiliary fresh water tank 42. The auxiliary fresh water tanks 42 illustrated in FIG. 2 are disposed on both the port and starboard sides of the hull 11 between the liquefied gas tanks 3 aligned longitudinally. By arranging the auxiliary fresh water tanks 42 on both the port and starboard sides, the left-right balance of the hull 11 can be maintained. Furthermore, the auxiliary fresh water tank 42 is preferably arranged approximately in the center of the hull 11 in the longitudinal direction. By arranging the auxiliary fresh water tank 42 approximately in the center of the hull 11 in the longitudinal direction, it is expected that the bending moment of the hull 11 will be alleviated. However, the arrangement of the auxiliary fresh water tank 42 is not limited to this embodiment, and the auxiliary fresh water tank 42 may be arranged on only one of the port and starboard sides of the hull 11, or the auxiliary fresh water tank 42 may be arranged at the bow or stern of the hull 11.

[0015] The multiple fresh water tanks 4 may include fresh water tanks other than the main fresh water tank 41 and the auxiliary fresh water tank 42. For example, fresh water tanks for each fresh water consumption purpose, such as a fresh water tank that stores fresh water used mainly as drinking water and a fresh water tank that stores fresh water used in the main engine boiler, may be installed on the liquefied gas carrier 1. Fresh water tanks other than the main fresh water tank 41 and the auxiliary fresh water tank 42 may be located in the cargo space 13, similar to the auxiliary fresh water tank 42, or may be located at the bow or stern.

[0016] <<Fresh Water Flow Channel System 40>> Figure 3 is a diagram showing the fresh water flow channel system 40 through which fresh water flows, and illustrates the flow of fresh water centered around a main fresh water tank 41. As shown in Figure 3, a fresh water supply main pipe 47 is connected to the main fresh water tank 41. The fresh water supply main pipe 47 is equipped with a main valve 44 and a hydrophore device 48 that adjusts the pressure of the fresh water. The hydrophore device 48 is composed of a feedwater pump 48a and a fresh water pressure tank 48b. The feedwater pump 48a pressurizes the fresh water in the fresh water supply main pipe 47 and sends it to the fresh water pressure tank 48b. The fresh water pressure tank 48b absorbs pressure fluctuations in the fresh water with enclosed compressed air, allowing fresh water at a stable pressure to flow downstream from the fresh water pressure tank 48b.

[0017] Fresh water supply branches to fresh water consumers are connected to the fresh water supply main 47 downstream of the hydrophore device 48. The fresh water supply branches include a domestic fresh water line 45, an engine room fresh water line 46, and a spray fresh water line 61. Each fresh water supply branch is provided with a supply valve 49, which switches on and off the supply of fresh water from the fresh water supply main 47 to each fresh water supply branch. The domestic fresh water line 45 supplies fresh water mainly to fresh water consumers on the bridge as domestic water. The engine room fresh water line 46 supplies fresh water to fresh water consumers other than the inert gas generator 2 in the engine room 14. The spray fresh water line 61 supplies fresh water to the fresh water nozzles 25 of the inert gas generator 2. However, the type and number of fresh water supply branches connected to the fresh water supply main 47 are not limited to those in this embodiment. In addition, at least one fresh water tank 4 other than the main fresh water tank 41 may be connected to the fresh water supply main pipe 47, and the fresh water from the fresh water tank 4 may be configured to flow out into the fresh water supply main pipe 47.

[0018] A first water supply line 53 is connected to the main fresh water tank 41, supplying fresh water from an outboard water supply source to the main fresh water tank 41. The first water supply line 53 is provided with a first water supply valve 54 that opens and closes the first water supply line 53. The outboard water supply source may be a fresh water storage container or fresh water generator located at a dock or port, a water supply ship, a water supply barge, etc. A fresh water supply pipe extending from the outboard water supply source is connected to a first water supply port 55 of the first water supply line 53, and when the first water supply valve 54 is opened, fresh water is supplied to the main fresh water tank 41 through the first water supply line 53. Note that although fresh water is mainly supplied to the main fresh water tank 41 from the outboard water supply source, fresh water may also be supplied to the main fresh water tank 41 from an onboard water generator.

[0019] A second water supply line 56 is connected to the auxiliary fresh water tank 42, supplying fresh water from an outboard water supply source to the auxiliary fresh water tank 42. The second water supply line 56 is provided with a second water supply valve 57 that opens and closes the second water supply line 56. A fresh water supply pipe extending from the outboard water supply source is connected to a second water supply port 58 of the second water supply line 56, and when the second water supply valve 57 is opened, fresh water is supplied to the auxiliary fresh water tank 42 through the second water supply line 56. In this embodiment, the first water supply port 55 and the second water supply port 58 are independent, but the second water supply port 58 may also be used in conjunction with the first water supply port 55.

[0020] The main fresh water tank 41 and the auxiliary fresh water tank 42 are connected by a transfer line 51. A transfer pump 52 is provided in the transfer line 51. Similarly, the main fresh water tank 41 and a fresh water tank 4 other than the auxiliary fresh water tank 42 may be connected by a transfer line. Note that if water flows from the auxiliary fresh water tank 42 to the main fresh water tank 41 by gravity, the transfer pump 52 may be omitted.

[0021] By operating the transfer pump 52, fresh water stored in the auxiliary fresh water tank 42 is transferred to the main fresh water tank 41 through the transfer line 51. By operating the hydrophore device 48, fresh water stored in the main fresh water tank 41 is supplied to the fresh water nozzle 25 of the inert gas generator 2 through the fresh water supply main pipe 47 and the spray fresh water line 61. In this way, the transfer line 51, the main fresh water tank 41, the fresh water supply main pipe 47, and the spray fresh water line 61 constitute a fresh water supply line 60 that supplies fresh water from the auxiliary fresh water tank 42 to the fresh water nozzle 25 of the inert gas generator 2 via the main fresh water tank 41.

[0022] <Configuration of Inert Gas Generator 2> Figure 4 is a schematic configuration diagram of the inert gas generator 2. The inert gas generator 2 shown in Figure 4 includes a combustion chamber 21 and a scrubber 23 connected to the combustion chamber 21. A burner 22 is provided in the combustion chamber 21, and high-temperature combustion exhaust gas with a low oxygen concentration is generated by combusting fuel oil supplied to the burner 22.

[0023] The combustion chamber 21 has a fresh water nozzle 25 that sprays fresh water into the combustion chamber 21. Fresh water is supplied to the fresh water nozzle 25 from the sub fresh water tank 42 via a fresh water supply line 60. The fresh water nozzle 25 sprays fresh water into the flow of high-temperature combustion exhaust gas generated in the combustion chamber 21.

[0024] The outlet of the combustion chamber 21 is connected to the inlet of a scrubber 23, and the combustion exhaust gas after contacting with the fresh water flows into the scrubber 23. The outlet of the scrubber 23 is connected to the liquefied gas tank 3 via an inert gas supply line 30.

[0025] The scrubber 23 has seawater nozzles 27 that spray seawater into the scrubber 23. The seawater nozzles 27 are supplied with seawater that flows into the seawater supply line 50 through the sea chest 16 by operation of the seawater pump 17. The seawater nozzles 27 may also be supplied with seawater stored in the ballast water tank 15. The seawater nozzles 27 spray seawater into the flow of combustion exhaust gas that flows in from the combustion chamber 21.

[0026] <<Operation Method of Inert Gas Generator 2>> The inert gas generated by the inert gas generator 2 is supplied to the liquefied gas tank 3 through the inert gas supply line 30 and used for gas substitution. Specifically, before the liquefied gas carrier 1 enters the dock and undergoes an inspection of the liquefied gas tank 3, the flammable gas remaining in the liquefied gas tank 3 is temporarily substituted with inert gas, and at this time, the inert gas is supplied from the inert gas generator 2 to the liquefied gas tank 3. Furthermore, after the inspection is completed and before the ship leaves the dock or after leaving the dock, and before loading into the liquefied gas tank 3, the air in the liquefied gas tank 3 is temporarily substituted with inert gas, and at this time, the inert gas is supplied from the inert gas generator 2 to the liquefied gas tank 3. However, the uses of the inert gas generated by the inert gas generator 2 are not limited to the above, and the inert gas generated by the inert gas generator 2 may be used for replenishing inert gas in the cargo space 13, etc.

[0027] 3 , during and / or before operation of the inert gas generator 2, the second water supply port 58 is connected to an external water supply source, fresh water is supplied to the auxiliary fresh water tank 42, and the fresh water is stored in the auxiliary fresh water tank 42. Note that the auxiliary fresh water tank 42 may be empty or may contain only a small amount of fresh water while the vessel is traveling. Alternatively, the auxiliary fresh water tank 42 may contain sufficient fresh water to suppress an increase in the bending moment of the hull 11 while the vessel is traveling.

[0028] During operation of the inert gas generator 2, the transfer pump 52 is operated to transfer fresh water from the auxiliary fresh water tank 42 to the main fresh water tank 41 through the transfer line 51. Furthermore, the main valve 44 and the supply valve 49 of the spray fresh water line 61 are opened, and the hydrophore device 48 is operated to supply fresh water from the main fresh water tank 41 to the fresh water nozzle 25 of the inert gas generator 2 through the fresh water supply main pipe 47 and the spray fresh water line 61. In this manner, fresh water from the auxiliary fresh water tank 42 is supplied to the fresh water nozzle 25 through the fresh water supply line 60. As a result, regardless of the size of the main fresh water tank 41, a sufficient amount of fresh water can be supplied to the fresh water nozzle 25 for the amount of fresh water required during operation of the inert gas generator 2. Furthermore, because the fresh water supply line 60 utilizes the main fresh water tank 41 and the fresh water supply main pipe 47 that are used during navigation, the hydrophore device 48, piping, etc., installed on the hull 11 can be reduced. Furthermore, by supplying water to the main fresh water tank 41 via the secondary fresh water tank 42 rather than supplying water directly from the dock to the main fresh water tank 41, it is possible to optimize the amount of fresh water received at the dock and the operation of the fresh water production equipment.

[0029] High-temperature flue gas is generated by the combustion of fuel oil in the burner 22 of the combustion chamber 21. The high-temperature flue gas first comes into contact with fresh water ejected from the fresh water nozzle 25 in the combustion chamber 21. This cools the flue gas through heat exchange between the flue gas and the fresh water. The flue gas leaving the combustion chamber 21 flows into the scrubber 23 and comes into contact with seawater ejected from the seawater nozzle 27. This causes particles entrained in the flue gas to be collected by the seawater and separated from the flue gas, and the flue gas is cooled through heat exchange between the flue gas and the seawater. The flue gas cooled by the fresh water, washed and cooled by the seawater, is discharged from the scrubber 23 as inert gas. The inert gas is supplied to the liquefied gas tank 3 through the inert gas supply line 30. The inert gas supplied to the liquefied gas tank 3 through the inert gas supply line 30 is used for gas replacement in the liquefied gas tank 3.

[0030] As described above, the combustion exhaust gas generated in the combustion chamber 21 is first-stage cooled by fresh water in the combustion chamber 21, and then second-stage washed and cooled by seawater in the scrubber 23. Since the temperature of the combustion exhaust gas is lowered in the first-stage washing, evaporation of seawater that comes into contact with the combustion exhaust gas in the second-stage washing is suppressed. Therefore, the salt content of the inert gas generated by the inert gas generator 2 is lower than that of inert gas generated by a conventional inert gas generator that is washed only with seawater.

[0031] The inert gas generated by the inert gas generator 2 has a lower salt content than conventional inert gas, and therefore the amount of salt adhering to the inner wall of the liquefied gas tank 3 to which the inert gas is supplied can be reduced. This makes it possible to prevent a decrease in the purity of the liquefied gas loaded in the liquefied gas tank 3 after gas replacement.

[0032] [Summary] The liquefied gas carrier 1 according to the first item of the present disclosure comprises: a liquefied gas tank 3 for storing liquefied gas; an inert gas generator 2 having a burner 22 for burning fuel, a fresh water nozzle 25 for spraying fresh water onto the combustion exhaust gas generated by the burner 22, and a seawater nozzle 27 for spraying seawater onto the combustion exhaust gas after the fresh water has been sprayed, and for generating inert gas to be supplied to the liquefied gas tank 3; a fresh water tank 42 for the inert gas generator (the auxiliary fresh water tank 42 in the above embodiment) for storing fresh water to be supplied to the inert gas generator 2; a fresh water supply line 60 for supplying fresh water from the fresh water tank 42 for the inert gas generator to the inert gas generator 2; and a seawater supply line 50 for supplying seawater to the inert gas generator 2. The vessel is equipped with a hull 11 on which a liquefied gas tank 3, an inert gas generator 2, a fresh water tank 42 for the inert gas generator, a fresh water supply line 60, and a seawater supply line 50 are mounted.

[0033] In the liquefied gas carrier 1 configured as described above, the combustion exhaust gas is washed in the inert gas generator 2 with fresh water supplied from the inert gas generator fresh water tank 42 and then washed with seawater, thereby reducing the salt content of the inert gas supplied from the inert gas generator 2 to the liquefied gas tank 3. This makes it possible to reduce the amount of salt that adheres to the inner wall of the liquefied gas tank 3 when gas in the liquefied gas tank 3 is replaced with the inert gas generated in the inert gas generator 2, and suppresses a decrease in the purity of the liquefied gas newly filled into the liquefied gas tank 3. The liquefied gas carrier 1 is further provided with the inert gas generator fresh water tank 42 that stores the fresh water used for spraying from the fresh water nozzle 25 in the inert gas generator 2, thereby making it possible to supply the amount of fresh water required for inert gas generation.

[0034] The liquefied gas carrier 1 according to the second item of the present disclosure is the liquefied gas carrier 1 according to the first item, and is equipped with a main fresh water tank 41 mounted on the hull 11 for storing fresh water consumed during navigation, and a fresh water supply line 60 supplies fresh water from a fresh water tank 42 for an inert gas generating device to the fresh water nozzle 25 via the main fresh water tank 41.

[0035] By providing both the inert gas generator fresh water tank 42 and the main fresh water tank 41, it is possible to supply a sufficient amount of fresh water to the fresh water nozzle 25 for the amount of fresh water required during operation of the inert gas generator 2. It is also possible to optimize the amount of fresh water received by the liquefied gas carrier 1 at dock and the operation of the fresh water generator. Furthermore, because the main fresh water tank 41 and a line connected to the main fresh water tank 41 can be used as part of the fresh water supply line 60, equipment used during navigation (e.g., the main valve 44 and hydrophore device 48) can be used to operate the inert gas generator 2.

[0036] The liquefied gas carrier 1 according to the third item of the present disclosure is the liquefied gas carrier 1 according to the second item, which is provided with a transfer line 51 for transferring fresh water from the fresh water tank 42 for the inert gas generator to the main fresh water tank 41.

[0037] According to the liquefied gas carrier 1 having the above configuration, the transfer line 51 can be closed during navigation, and the fresh water tank 42 for the inert gas generator can be separated from the main fresh water tank 41. When the inert gas generator 2 is in operation, the main fresh water tank 41 and the fresh water tank 42 for the inert gas generator can be connected by the transfer line 51, and fresh water can be transferred from the fresh water tank 42 for the inert gas generator to the main fresh water tank 41.

[0038] The liquefied gas carrier 1 relating to the fourth item of the present disclosure is a liquefied gas carrier 1 relating to the second or third item, which is provided with fresh water lines 45, 46 that supply fresh water from the main fresh water tank 41 to fresh water consumption sections other than the inert gas generator 2.

[0039] According to the liquefied gas carrier 1 having the above-described configuration, the main fresh water tank 41 can be used to store fresh water to be supplied to fresh water consumption sections other than the inert gas generator 2 during navigation, and can be used as part of the fresh water supply line 60 when the inert gas generator 2 is in operation.

[0040] The liquefied gas carrier 1 relating to the fifth item of the present disclosure is a liquefied gas carrier 1 relating to any of the first to fourth items, which is equipped with a water supply line 56 that can be connected to an offboard water supply source and that sends fresh water from the offboard water supply source to the fresh water tank 42 for the inert gas generating device.

[0041] According to the liquefied gas carrier 1 having the above configuration, fresh water can be supplied from the fresh water tank 42 for the inert gas generator to the inert gas generator 2 while water is being supplied to the fresh water tank 42 for the inert gas generator during or before operation of the inert gas generator 2.

[0042] The liquefied gas carrier 1 relating to the sixth item of the present disclosure is a liquefied gas carrier 1 relating to any of the first to fifth items, in which the fresh water tank 42 for the inert gas generating device is arranged approximately in the center of the hull 11 in the longitudinal direction.

[0043] According to the liquefied gas carrier 1 having the above-described configuration, the bending moment of the hull 11 can be expected to be alleviated by the fresh water tank 42 for the inert gas generator.

[0044] The liquefied gas carrier 1 relating to the seventh item of the present disclosure is a liquefied gas carrier 1 relating to any of the first to fifth items, in which the hull 11 has an engine room 14 located at the stern and a cargo space 13 located on the bow side of the engine room 14, the inert gas generator 2 is located in the engine room 14, and the liquefied gas tank 3 and the fresh water tank 42 for the inert gas generator are located in the cargo space 13.

[0045] According to the liquefied gas carrier 1 configured as described above, compared to when the inert gas generator fresh water tank 42 is disposed below deck at the stern, there is a higher degree of freedom in the placement of the inert gas generator fresh water tank 42, and it is also possible to increase the tank size of the inert gas generator fresh water tank 42. Furthermore, by placing the inert gas generator fresh water tank 42 in the center part of the hull 11 in the longitudinal direction, it is possible to suppress an increase in the required strength of the hull due to mitigation of the bending moment of the hull 11.

[0046] The foregoing disclosure has been presented for purposes of illustration and description and is not intended to limit the disclosure to the form disclosed herein. For example, in the foregoing Detailed Description, various features of the disclosure are grouped together in a single embodiment for the purpose of streamlining the disclosure, but some of the features may also be combined. Furthermore, multiple features included in the present disclosure may be combined into alternative embodiments, configurations, or aspects other than those discussed above.

[0047] 1: Liquefied gas carrier 2: Inert gas generator 3: Liquefied gas tank 4: Fresh water tank 11: Hull 13: Cargo space 14: Engine room 22: Burner 23: Scrubber 25: Fresh water nozzle 27: Seawater nozzle 41: Main fresh water tank 42: Sub fresh water tank (fresh water tank for inert gas generator) 45, 46: Fresh water line 50: Seawater supply line 51: Transfer line 60: Fresh water supply line

Claims

1. A liquefied gas carrier comprising: a liquefied gas tank for storing liquefied gas; an inert gas generator having a liquefied gas tank, a burner for burning fuel, a fresh water nozzle for spraying fresh water onto combustion exhaust gas generated by the burner, and a seawater nozzle for spraying seawater onto the combustion exhaust gas after the fresh water has been sprayed, and for generating inert gas to be supplied to the liquefied gas tank; a fresh water tank for the inert gas generator for storing fresh water to be supplied to the inert gas generator; a fresh water supply line for supplying fresh water from the fresh water tank for the inert gas generator to the inert gas generator; a seawater supply line for supplying seawater to the inert gas generator; and a hull on which the liquefied gas tank, the inert gas generator, the fresh water tank for the inert gas generator, the fresh water supply line, and the seawater supply line are mounted.

2. A liquefied gas carrier as described in claim 1, further comprising a main fresh water tank mounted on the hull for storing fresh water consumed during navigation, and the fresh water supply line supplies fresh water from the fresh water tank for the inert gas generator to the fresh water nozzle via the main fresh water tank.

3. A liquefied gas carrier according to claim 2, comprising a transfer line for transferring fresh water from the fresh water tank for the inert gas generator to the main fresh water tank.

4. A liquefied gas carrier according to claim 2 or 3, comprising a fresh water line for supplying fresh water from the main fresh water tank to a fresh water consuming section other than the inert gas generating device.

5. A liquefied gas carrier according to any one of claims 1 to 3, comprising a water supply line connectable to an outboard water supply source and supplying fresh water from the outboard water supply source to the fresh water tank for the inert gas generator.

6. A liquefied gas carrier according to any one of claims 1 to 3, wherein the fresh water tank for the inert gas generator is arranged approximately in the center of the hull in the longitudinal direction.

7. A liquefied gas carrier according to any one of claims 1 to 3, wherein the hull has an engine room located at the stern and a cargo space located bowward of the engine room, the inert gas generator is located in the engine room, and the liquefied gas tank and the fresh water tank for the inert gas generator are located in the cargo space.

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