AU2015329208A1

AU2015329208A1 - Liquefied hydrogen transferring system

Info

Publication number: AU2015329208A1
Application number: AU2015329208A
Authority: AU
Inventors: Seiro ITO; Eiji KAWAGOE; Tomonori TAKASE; Tomoaki UMEMURA; Shuntaro UNNO
Original assignee: Kawasaki Heavy Industries Ltd; Kawasaki Jukogyo KK
Current assignee: Kawasaki Motors Ltd
Priority date: 2014-10-10
Filing date: 2015-09-28
Publication date: 2017-05-18
Anticipated expiration: 2035-09-28
Also published as: JP6423235B2; AU2015329208B2; JP2016079998A; CN106687738B; WO2016056414A1; CN106687738A

Abstract

The purpose of the present invention is to enable a mixed gas, which is generated when a peripheral part of a loading arm is purged with an inert gas, to be collected without being expelled into the atmosphere and to enable a hydrogen gas, which is extracted when liquefied hydrogen is charged into a liquefied hydrogen storage tank on a liquefied hydrogen carrying vessel or on the shore, to be collected with no change in the high purity thereof. Provided is a liquefied hydrogen transferring system (1) that transfers liquefied hydrogen between a first tank (2) on the shore and a second tank (3) on a liquefied hydrogen carrying vessel. The liquefied hydrogen transferring system (1) comprises: a first transferring means (4) that can transfer liquefied hydrogen between the first tank (2) and the second tank (3) via a loading arm (4a); a second transferring means (5) that can transfer a hydrogen gas to the second tank (3) or from the second tank (3) via a loading arm (5a); inert gas supplying means (7A, 7B) that can supply an inert gas to the second tank (3) when the second tank (3) is empty; and a third transferring means (6) that can collect a mixed gas made up of the inert gas supplied from the inert gas supplying means (7A, 7B) and the hydrogen gas remaining inside the second tank (3) and transfer the mixed gas to the shore.

Description

LIQUEFIED HYDROGEN TRANSFERRING SYSTEM

TECHNICAL FIELD

[0001] The present invention relates to a liquid hydrogen transportation 5 system which transports liquid hydrogen between a liquid hydrogen transportation ship and a liquid hydrogen base.

BACKGROUND ART

[0002] Liquid gas transportation systems for transporting liquid gas between 10 a liquid gas transportation ship which marine transports liquid gas (e.g., LNG) and a liquid gas storage tank placed on a land are put in practical use. A system which transports liquid gas between a tank placed on a liquid gas transportation ship side and a tank placed on a receiving base side is disclosed in Patent Document 1. This system includes transport piping for 15 transporting liquid gas between the liquid-gas-transportation-ship-side tank and the receiving-base-side tank through a loading arm, and a return gas pipe for transporting boil-off gas (BOG) between the liquid-gas-transportation ship-side tank and the receiving-base-side tank when transporting liquid gas through the transport piping, so as to substantially keep an internal pressure of 20 the liquid-gas-transportation-ship-side tank.

[0003] Although it is not described in Patent Document 1, in a case of transporting fuel gas (such as natural gas and hydrogen) as liquid, a work of replacing burnable gas which remains inside the transport piping or the return gas pipe with inactive gas, such as nitrogen gas, is performed when the 25 transportation is completed. Further, in maintenance, a work of replacing 2/21 fuel gas which remains inside the liquid-gas-transportation-ship-side tank with inactive gas, such as nitrogen gas, is also performed. Mixture gas generated at the time of such gas replacement is dischargeable to the atmosphere if the amount is small; however, if the amount is large, it needs to be collected. As 5 a specific collecting method, usually, the gas is returned back to a liquid layer inside the tank through the transport piping or the gas return pipe.

[0004] Note that, when starting the transportation, a work of replacing gas inside the transport piping or the return gas pipe or, depending on the situation, inside the liquid-gas-transportation-ship-side tank with fuel gas is performed, 10 and mixture gas generated here is also similarly processed.

REFERENCE DOCUMENT OF CONVENTIONAL ART

Patent Document [0005]

15 Patent Document 1: JP2000-117429A DESCRIPTION OF THE INVENTION [Problems to be Solved by the Invention] [0006] There are many ways to use liquid hydrogen for other than power 20 generation, and high degree of purity is required. For this reason, the above described system is not suitable for transporting liquid hydrogen.

[0007] That is, since the system described above is simply equipped with the pipings of two systems which are the transport piping for liquid gas transportation and the gas return pipe, mixture gas (the mixture gas containing 25 inactive gas, hydrogen gas, etc.) generated at the time of gas replacement 3/21 flows to each of the transport piping and the gas return pipe. Therefore each of the pipings may be contaminated (polluted by the mixture gas) and the purity of hydrogen gas may be lowered.

[0008] The purpose of the present invention is to provide a liquid hydrogen 5 transportation system separable and collectable of mixture gas generated at the time of gas replacement, hydrogen gas and liquid hydrogen inside tanks. [Summary of the Invention] [0009] According to one aspect of the present invention, a liquid hydrogen transportation system is provided which is for transporting liquid hydrogen 10 between a first tank placed on a land side and a second tank placed on a liquid hydrogen transportation ship side, the first and second tanks storable of liquid hydrogen. The system includes a first transportation means transportable of liquid hydrogen between the first and second tanks through a loading arm, a second transportation means transportable of hydrogen gas either to or from 15 the second tank through a loading arm, an inactive gas supply means suppliable of inactive gas to the second tank when the second tank is not loaded, and a third transportation means collectable of mixture gas containing inactive gas supplied from the inactive gas supply means and hydrogen gas remaining inside the second tank, and transportable of the mixture gas to the 20 land side.

[0010] According to the above configuration, liquid hydrogen is transportable between the first and second tanks by the first transportation means, and here, it is possible to transport though the second transportation means hydrogen gas of high purity which is taken out from one of the first and second tanks where 25 liquid hydrogen is charged, and collect it. Further, when the second tank is 4/21 not loaded, for example, at the time of entering a dock, inactive gas is suppliable from the inactive gas supply means to the second tank. Here, by the third transportation means, it is possible to collect mixture gas containing inactive gas supplied from the inactive gas supply means and hydrogen gas 5 remaining inside the second tank, transport it to the land side to be collected.

[0011] The inactive gas supply means may be suppliable of inactive gas to the first and second transportation means around the time of a work of transporting liquid hydrogen between the first and second tanks. The third transportation means may be connected to each of the first and second 10 transportation means, collectable of mixture gas containing inactive gas supplied from the inactive gas supply means and hydrogen gas remaining inside the first and second transportation means, and transportable of the mixture gas to the land side.

[0012] According to the above configuration, for example, after liquid 15 hydrogen is transported, hydrogen gas remains inside the first and second transportation means. The mixture gas containing the inactive gas supplied by the inactive gas supply means to the first and second transportation means and the hydrogen gas remaining inside the first and second transportation means is collectable by transporting to the land side by the third transportation 20 means.

[0013] When the liquid hydrogen transportation ship is alongside of a pier, a purge may be performed with inactive gas by supplying the inactive gas to the first and second transportation means, and mixture gas containing inactive gas discharged during the purge and air may be transported to the land side by the 25 third transportation means. 5/21 [0014] After the purge with the inactive gas, a purge may be performed with hydrogen gas by supplying the hydrogen gas to the first and second transportation means, and mixture gas containing inactive gas discharged during the purge and hydrogen gas may be transported to the land side by the 5 third transportation means.

[0015] When loading liquid hydrogen to the second tank by the first transportation means, hydrogen gas inside the second tank may be transported to the land side by the second transportation means.

[0016] A part of the second transportation means on the land side from the 10 loading arm may include a cylindrical passage between an outer cylindrical pipe fitted onto a land-side part of the first transportation means and the first transportation means. According to the above configuration, by flowing low-temperature hydrogen gas to the cylindrical passage, it is possible to avoid heat input to the land-side part of the first transportation means 15 [0017] A part of the third transportation means on the land side from the loading arm may include a cylindrical passage between an outer cylindrical pipe fitted onto a land-side part of the second transportation means and the second transportation means. According to the above configuration, by flowing low-temperature mixture gas to the cylindrical passage, it is possible 20 to avoid heat input to the land-side part of the second transportation means. [Effects of the Invention] [0018] According to the present invention, it is possible to separate and collect mixture gas generated at the time of gas replacement, hydrogen gas and liquid hydrogen inside tanks. 25 6/21

BRIEF DESCRIPTION OF DRAWINGS

[0019]

Fig. 1 is a schematic configuration view of a liquid hydrogen transportation system according to a first embodiment of the present invention. 5 Fig. 2 is an operational view illustrating an operation when a liquid hydrogen transportation ship is alongside of a pier.

Fig. 3 is an operational view when a hydrogen gas purge starts after a nitrogen gas purge.

Fig. 4 is an operational view when loading of liquid hydrogen starts. 10 Fig. 5 is an operational view when the loading of liquid hydrogen ends.

Fig. 6 is an operational view before the liquid hydrogen transportation ship enters a dock.

Fig. 7 is an operational view after the liquid hydrogen transportation 15 ship enters the dock.

Fig. 8 is a schematic configuration view of a liquid hydrogen transportation system according to a second embodiment.

Fig. 9 is a cross-sectional view of a triple pipe of Fig. 8.

20 MODES FOR CARRYING OUT THE INVENTION

[0020] Hereinafter, modes for carrying out the present invention are described based on embodiments.

First Embodiment 25 [0021] Fig. 1 illustrates a liquid hydrogen transportation system 1 according 7/21 to a first embodiment. This liquid hydrogen transportation system 1 transports liquid hydrogen between a first tank 2 placed on a land side, storable of liquid hydrogen, and a second tank 3 placed on a liquid hydrogen transportation ship side, storable of liquid hydrogen. 5 This liquid hydrogen transportation system 1 includes a first transportation means 4 (first transportation line), a second transportation means 5 (second transportation line), a third transportation means 6 (third transportation line), inactive gas supply means 7A and 7B, and hydrogen gas charging means 8A and 8B (branch pipes). In the description below, the 10 “automatic valve” is simply described as the “valve.” [0022] The first transportation means 4 is transportable of liquid hydrogen through a loading arm 4a between the first and second tanks 2 and 3. A major part of the first transportation means 4 is structured by a vacuum heat-insulation dual pipe, of which one end is connected to the first tank 2 and 15 the other end is connected to the second tank 3. The loading arm 4a is placed in an intermediate section of the first transportation means 4, and the loading arm 4a is provided with an emergency removal device 4b and a valve 4c. The boundary part between the land side and the ship side of the first transportation means 4 is connected by a bayonet joint 4d. A part of the first 20 transportation means 4 near the loading arm 4a (on the first tank 2 side) is provided with a valve 4e, and a part of the first transportation means 4 near the second tank 3 is provided with a valve 4f, and also a valve 4g is provided between the bayonet joint 4d and the valve 4f.

[0023] The second transportation means 5 is transportable of hydrogen gas 25 through a loading arm 5a to/from the second tank 3, and a major part thereof is 8/21 structured by a single pipe, of which one end is connected to a hydrogen gas tank 9 and the other end is connected to the second tank 3. The loading arm 5 a is placed in an intermediate part of the second transportation means 5, and the loading arm 5 a is provided with an emergency removal device 5b and a 5 valve 5c. The boundary part between the land side and the ship side of the second transportation means 5 is connected by a bayonet joint 5d.

[0024] A part of the second transportation means 5 near the loading arm 5a (on the hydrogen gas tank 9 side) is provided with a valve 5e, and a part of the second transportation means 5 near the second tank 3 is provided with a valve 10 5f, and also a valve 5g is provided between the bayonet joint 5d and the valve 5f.

[0025] The inactive gas supply means 7A is suppliable of inactive gas (N2 gas) to the first transportation means 4, and one end of this inactive gas supply means 7A is connected to an N2 gas tank 10 and the other end is connected 15 between the valve 4c and the bayonet joint 4d of the first transportation means 4. The inactive gas supply means 7A is provided with a valve 7a near the N2 gas tank 10.

[0026] The inactive gas supply means 7B is suppliable of inactive gas (nitrogen gas) to the second transportation means 5, and one end of this 20 inactive gas supply means 7B is connected to the N2 gas tank 10 and the other end is connected between the valve 5c and the bayonet joint 5d of the second transportation means 5. The inactive gas supply means 7B is provided with a valve 7b.

[0027] The ship side of the third transportation means 6 is connected to the 25 first and second transportation means 4 and 5 via bypass pipes 12 and 13 9/21 having valves 12a and 13a, respectively. This third transportation means 6 is transportable to the land side through a loading arm 6a, of mixture gas discharged when a purge is performed in peripheral parts of the loading arms 4a and 5a of the first and second transportation means 4 and 5 by using N2 gas 5 or hydrogen gas (GH2), and a major part thereof is structured by a single pipe. One end of the third transportation means 6 is connected to a mixture gas treatment device 11 and the other end of the third transportation means 6 is connected to the second tank 3.

[0028] The loading arm 6a is placed in an intermediate section of the third 10 transportation means 6, and the loading arm 6a is provided with an emergency removal device 6b and a valve 6c. The boundary part between the land side and the ship side of the third transportation means 6 is connected by a bayonet joint 6d. A part of the third transportation means 6 near the loading arm 6a (on the mixture gas treatment device 11 side) is provided with a valve 6e, and 15 a part of the third transportation means 6 near the second tank 3 is provided with a valve 6f, and also a valve 6g is provided between the bayonet joint 6d and the valve 6f.

[0029] To enable the supply of hydrogen gas from the hydrogen gas tank 9 to the inactive gas supply means 7A, the branch pipe 8A branching from the 20 second transportation means 5 and connected to the inactive gas supply means 7A is provided, and a valve 8a is provided to this branch pipe 8A. Further, to enable the supply of hydrogen gas from the hydrogen gas tank 9 to the inactive gas supply means 7B, the branch pipe 8B branching from the second transportation means 5 and connected to the inactive gas supply means 7B is 25 provided, and a valve 8b is provided to this branch pipe 8B. 10/21 [0030] Next, an example of loading liquid hydrogen from the first tank 2 to the second tank 3 when the liquid hydrogen transportation ship leaves a port in a loaded state and arrives at a pier of a base is described. In this case, the first tank 2 is charged with liquid hydrogen and the second tank 3 contains a 5 small amount of liquid hydrogen and hydrogen gas. At first, with reference to Fig. 2, an N2 gas purge is described, in which air remaining in the peripheral parts of the bayonet joints 4d and 5d of the first and second transportation means 4 and 5 after the bayonet joints 4d to 6d of the first to third transportation means 4 to 6 are connected is purged (replaced) with N2 gas 10 (inactive gas).

[0031] As illustrated in Fig. 2, the valves 4c, 4e, 5c, 5e, 4f to 6f, 8a and 8b are closed, and the other valves are kept opened. N2 gas is supplied from the inactive gas supply means 7A and 7B to the first and second transportation means 4 and 5. From the first and second transportation means 4 and 5, 15 mixture gas containing the N2 gas and air is transported through the bypass pipes 12 and 13, further through the third transportation means 6, to the mixture gas treatment device 11, and the N2 purge is executed for a given period of time and then ends. As a result of this N2 gas purge, N2 gas is charged between the valves 4c and 5c and the valves 4f and 5f of the first and 20 second transportation means 4 and 5, respectively.

[0032] Next, a GH2 purge is described, in which after the N2 gas purge described above ends, N2 gas remaining in the peripheral parts of the bayonet joints 4d and 5d of the first and second transportation means 4 and 5 is purged with GH2 (hydrogen gas). This GH2 purge is performed to prevent N2 gas 25 from flowing into the second tank 3 when loading liquid hydrogen. 11/21 [0033] As illustrated in Fig. 3, the valves 4c, 4e, 4g, 5c, 5e, 5g, 4f to 6f, 7a and 7b are closed, and the other valves are kept opened. GH2 (hydrogen gas) is supplied from the hydrogen gas tank 9 to the peripheral part of the bayonet joint 4d of the first transportation means 4, and GH2 is supplied from the hydrogen gas tank 9 to the peripheral part of the bayonet joint 5d of the second transportation means 5. Mixture gas containing the N2 gas and GH2 in the first transportation means 4 is transported from the bypass pipe 12 to the mixture gas treatment device 11 through the third transportation means 6, and mixture gas containing the N2 gas and GH2 in the second transportation means 5 is transported from the bypass pipe 13 to the mixture gas treatment device 11 through the third transportation means 6.

[0034] GH2 is eliminated by means of, for example, combustion in this mixture gas treatment device 11, and N2 gas is contained in a given tank (e.g., N2 gas tank 10). As a result of this GH2 purge, the first and second transportation means 4 and 5 become the state where they are charged with GH2.

[0035] Next, when loading liquid hydrogen from the first tank 2 to the second tank 3, as illustrated in Fig. 4, the valves 6f, 7a, 7b, 8a, 8b, 12a and 13a are closed, and the other valves are kept opened. Liquid hydrogen is transported from the first tank 2 to the second tank 3 through the first transportation means 4, and GH2 inside the second tank 3 is transported to the hydrogen gas tank 9 through the second transportation means 5. In this manner, it is possible to collect at the hydrogen gas tank 9, GH2 at high purity inside the second tank 3.

[0036] Next, an N2 gas purge after loading liquid hydrogen is described.

This N2 gas purge is performed to prevent GH2 from coming in 12/21 contact with oxygen within air and exploding when the bayonet joints 4d to 5d are separated for leaving the pier. As illustrated in Fig. 5, the valves 4c, 4e, 5c, 5e, 4f to 6f, 8a and 8b are closed, and the other valves are kept opened. N2 gas is supplied from the N2 gas tank 10 to the bayonet joint peripheral parts 5 of the first and second transportation means 4 and 5 by the inactive gas supply means 7A and 7B, respectively. Mixture gas containing N2 gas and GH2 is transported from the first and second transportation means 4 and 5 through the bypass pipes 12 and 13, further through the third transportation means 6, to the mixture gas treatment device 11, and the N2 gas purge is executed for a given 10 period of time and then ends.

[0037] As a result of this N2 gas purge, N2 gas is charged between the valves 4e and 5e and the valves 4f and 5f of the first and second transportation means 4 and 5, respectively. Then, the bayonet joints 4d to 6d are separated and the liquid hydrogen transportation ship leaves the pier. 15 [0038] In the above description, the case where liquid hydrogen is loaded from the first tank 2 to the second tank 3 is described as an example; however, also in a case where liquid hydrogen is unloaded from the second tank 3 to the first tank 2, similarly to the above description, the connecting of the bayonet joints 4d to 6d, the N2 purge of the first and second transportation means 4 and 20 5, the GH2 purge of the first and second transportation means 4 and 5, the unloading of liquid hydrogen, the N2 gas purge of the first and second transportation means 4 and 5, and the separation of the bayonet joints 4d to 6d may be performed in this order.

[0039] Next, an N2 purge for replacing the inside of the second tank 3 with N2 25 gas before the liquid hydrogen transportation ship enters a dock for periodic 13/21 checkup, repairing etc., is described. This N2 gas purge is performed to replace all GH2 inside the second tank 3 with N2 gas when the second tank 3 is not loaded.

As illustrated in Fig. 6, the valves 4c, 4e, 5c, 5e, 5f, 7b, 8a, 8b and 13a 5 are closed, and the other valves are kept opened. N2 gas is supplied from the N2 gas tank 10 by the inactive gas supply means 7A, to the second tank 3 through the first transportation means 4. GH2 inside the second tank 3 is transported to the mixture gas treatment device 11 through the third transportation means 6. Note that, there is also a case where a purge of the 10 bayonet joint peripheral part of the second transportation means 5 is then performed with N2 gas.

[0040] Next, a GH2 purge for replacing the inside of the second tank 3 with GH2 after the entrance to the dock described above, is described. This GH2 purge is performed to replace all N2 gas inside the second tank 3 with GH2. 15 As illustrated in Fig. 7, the valves 4c, 4e, 4f, 7a, 7b, 8a, 12a and 13a are closed, and the other valves are kept opened. GH2 gas is supplied from the hydrogen gas tank 9 to the second tank 3 through the second transportation means 5. Mixture gas containing N2 gas inside the second tank 3, mixed with GH2, is transported to the mixture gas treatment device 11 through the third 20 transportation means 6. Then, an N? gas purge in which GH2 of the bayonet joint peripheral part of the second transportation means 5 is replaced with N2 gas is performed and then the ship leaves the dock and starts to navigate.

[0041] The operations and effects of the liquid hydrogen transportation system 1 above are described. 25 Liquid hydrogen is transportable between the first and second tanks 2 14/21 and 23 by the first transportation means 4, and here, it is possible to transport hydrogen gas taken out from the second tank 3 where liquid hydrogen is charged, though the second transportation means 5 while remaining to be at high purity, and collect it in the hydrogen gas tank 9. 5 [0042] In the case of purging the bayonet joint peripheral parts of the first and second transportation means 4 and 5 with N2 gas when the liquid hydrogen transportation ship is alongside of the pier, N2 gas is supplied to the first and second transportation means 4 and 5 from the inactive gas supply means 7A and 7B, respectively, and the valves 12a and 13a of the bypass pipes 12 and 13 10 are opened. Thus, it becomes possible to take out the mixture gas containing N2 gas and air from the third transportation means 6 after the purge, and transport it to the mixture gas treatment device 11 to be collected.

[0043] After the N2 gas purge of the first and second transportation means 4 and 5, since the GH2 purge is performed in the bayonet joint peripheral parts 15 of the first and second transportation means 4 and 5, it is possible to surely prevent that N2 gas flows into the second tank 3 when loading liquid hydrogen into the second tank 3. Further, after the loading of liquid hydrogen, since the N2 gas purge is performed in the bayonet joint peripheral parts of the first and second transportation means 4 and 5, even when the bayonet joints 4d to 20 6d are separated, GH2 does not come into contact with oxygen within air. Thus, it is possible to secure safety.

[0044] In entering the dock, since N2 gas is supplied from the N2 gas tank 10 to the second tank 3 by the inactive gas supply means 7A, it is possible to secure safety in working at the dock. After entering the dock, since GH2 is 25 charged in to the second tank 3 and the bayonet joint peripheral parts of the 15/21 first and second transportation means 4 and 5 become the state where they are charged with N2 gas, it is possible to restore the state before entering the dock.

Second Embodiment 5 [0045] A liquid hydrogen transportation system 1A of a second embodiment is described with reference to Figs. 8 and 9.

Components same as those of the liquid hydrogen transportation system 1 of the first embodiment are denoted with the same reference characters and the description thereof is omitted, and structures which differ 10 from the liquid hydrogen transportation system 1 are mainly described. 25 [0046] The structure of a part of the second transportation means 5 on the land side from the loading arm 5a is changed, and a part of the first transportation means 4 on the land side from the loading arm 4a is integrally structured with the land-side part of the second transportation means 5. As 15 illustrated in Fig. 9, at least the land-side part of the first transportation means 4 is structured by a vacuum heat-insulation dual pipe 40 comprised of an inner pipe 41 and an outer pipe 42. An outer cylindrical pipe 43 is fitted onto this vacuum heat-insulation dual pipe 40 with a cylindrical passage 44 formed therebetween, a passage on the inner side of the inner pipe 41 of the vacuum 20 heat-insulation dual pipe 40 is provided as the liquid hydrogen passage of the first transportation means 4 and the cylindrical passage 44 described above is provided as a part of the second transportation means 5. By flowing low-temperature hydrogen gas to the outside of the vacuum heat-insulation dual pipe 40 as above, it is possible to avoid heat input to the vacuum heat-insulation dual pipe 40. 16/21 [0047] Next, examples of partially changing the embodiments are described. (1) The following structure may be adopted by applying the idea of the second embodiment to the second and third transportation means 5 and 6. A part of the third transportation means 6 on the land side from the loading arm 5 6a has a structure including a cylindrical passage (not illustrated) between an outer cylindrical pipe (not illustrated) fitted onto the land-side part of the second transportation means 5, and the second transportation means 5.

[0048] (2) The N2 gas tank 10 may be equipped on the liquid hydrogen transportation ship side and the hydrogen gas tank 9 may also be equipped on 10 the liquid hydrogen transportation ship side. (3) It is needless to say that a person skilled in the art can implement the embodiments with various changes, and the present invention includes such embodiments.

15 INDUSTRIAL APPLICABILITY

[0049] The present invention provides a liquid hydrogen transportation system enabling transportation of liquid hydrogen between a first tank placed on a land side and storable of liquid hydrogen and a second tank placed on a liquid hydrogen transportation ship side. 20

DESCRIPTION OF REFERENCE CHARACTERS

[0050] 1, 1A Liquid Hydrogen Transportation System 2 First Tank 25 3

Second Tank 17/21 4 First Transportation Means 4a Loading Arm 5 Second Transportation Means 5a Loading Arm 6 Third Transportation Means 6a Loading Arm 7A, 7B Inactive Gas Supply Means 10 N2 Gas Tank 40 Vacuum Heat-insulation Dual Pipe 43 Outer Cylindrical Pipe 44 Cylindrical Passage

Claims

1. A liquid hydrogen transportation system for transporting liquid hydrogen between a first tank placed on a land side and a second tank placed on a liquid hydrogen transportation ship side, the first and second tanks storable of liquid hydrogen, comprising: a first transportation means transportable of liquid hydrogen between the first and second tanks through a loading arm; a second transportation means transportable of hydrogen gas either to or from the second tank through a loading arm; an inactive gas supply means suppliable of inactive gas to the second tank when the second tank is not loaded; and a third transportation means collectable of mixture gas containing inactive gas supplied from the inactive gas supply means and hydrogen gas remaining inside the second tank, and transportable of the mixture gas to the land side.

2. The liquid hydrogen transportation system of claim 1, wherein the inactive gas supply means is suppliable of inactive gas to the first and second transportation means around the time of a work of transporting liquid hydrogen between the first and second tanks, and wherein the third transportation means is connected to each of the first and second transportation means, collectable of mixture gas containing inactive gas supplied from the inactive gas supply means and hydrogen gas remaining inside the first and second transportation means, and transportable of the mixture gas to the land side.

3. The liquid hydrogen transportation system of claim 2, wherein when the liquid hydrogen transportation ship is alongside of a pier, a purge is performed with inactive gas by supplying the inactive gas to the first and second transportation means, and mixture gas containing inactive gas discharged during the purge and air is transported to the land side by the third transportation means.

4. The liquid hydrogen transportation system of claim 3, wherein after the purge with the inactive gas, a purge is performed with hydrogen gas by supplying the hydrogen gas to the first and second transportation means, and mixture gas containing inactive gas discharged during the purge and hydrogen gas is transported to the land side by the third transportation means.

5. The liquid hydrogen transportation system of claim 4, wherein when loading liquid hydrogen to the second tank by the first transportation means, hydrogen gas inside the second tank is transported to the land side by the second transportation means.

6. The liquid hydrogen transportation system of claim 2, wherein a part of the second transportation means on the land side from the loading arm includes a cylindrical passage between an outer cylindrical pipe fitted onto a land-side part of the first transportation means and the first transportation means.

7. The liquid hydrogen transportation system of claim 2, wherein a part of the third transportation means on the land side from the loading arm includes a cylindrical passage between an outer cylindrical pipe fitted onto a land-side part of the second transportation means and the second transportation means.