WO2024166241A1

WO2024166241A1 - Liquid hydrogen storage equipment, floating structure, and inter-tank gas supply method for multi-shell tank

Info

Publication number: WO2024166241A1
Application number: PCT/JP2023/004137
Authority: WO
Inventors: 宏之武田; 貴志下垣; 晴彦冨永; 祐紀木村
Original assignee: 川崎重工業株式会社
Priority date: 2023-02-08
Filing date: 2023-02-08
Publication date: 2024-08-15

Abstract

Liquid hydrogen storage equipment comprising: a multi-shell tank having an inner tank containing liquid hydrogen, an outer tank surrounding the inner tank, and a heat insulation layer disposed between the inner and outer tanks; a BOG line which is connected to the inner tank and from which boil-off gas of liquid hydrogen generated in the inner tank flows out; a heat exchanger that heats the boil-off gas; an inter-tank gas supply line for supplying the heated boil-off gas between the inner and outer tanks of the multi-shell tank; and a compressor that pressure-feeds the heated boil-off gas to the inter-tank gas supply line.

Description

Liquid hydrogen storage facility, floating structure, and method for supplying gas between tanks of multi-shell tank

This disclosure relates to a liquid hydrogen storage facility equipped with a multi-shell tank for storing liquid hydrogen.

Liquid hydrogen carriers equipped with liquid hydrogen storage equipment are known. The liquid hydrogen storage equipment includes a liquid hydrogen tank that contains liquid hydrogen, and loading and unloading equipment for lifting and unloading liquid hydrogen into the liquid hydrogen tank. Liquid hydrogen tanks are required to have high thermal insulation properties, and a multi-shell tank that has an inner tank, an outer tank surrounding the inner tank, and a thermal insulation layer disposed between the inner tank and the outer tank is known as such a liquid hydrogen tank. For example, Patent Document 1 discloses this type of multi-shell tank.

The multi-shell tank of Patent Document 1 comprises an inner tank that contains liquefied gas, and an outer tank that contains the inner tank. Between the inner and outer tanks, a heat insulating material is placed to cover the outer surface of the inner tank. In addition, boil-off gas discharged from the top of the inner tank is supplied between the inner and outer tanks, and the space between the tanks is filled with boil-off gas produced by vaporization of the liquefied gas.

International Publication No. WO2020/202578

In a multi-shell tank like the one described above, the minimum gas temperature that can be stored inside the inner tank is different from that between the inner and outer tanks. The inner tank has the low-temperature resistance to store low-temperature liquefied gas and its boil-off gas. On the other hand, the low-temperature resistance of the insulation material placed between the inner and outer tanks is lower than that of the inner tank. Therefore, if the boil-off gas generated in the inner tank is directly supplied between the inner and outer tanks and the low-temperature boil-off gas comes into contact with the insulation material, there is a risk that the insulation material will freeze and be altered.

This disclosure has been made in consideration of the above circumstances, and its purpose is to supply boil-off gas of liquid hydrogen between the inner and outer vessels in a multi-shell tank having an inner vessel that contains liquid hydrogen, an outer vessel that surrounds the inner vessel, and a thermal insulation layer disposed between the inner and outer vessels without damaging the thermal insulation layer.

In order to solve the above problems, a liquid hydrogen storage facility according to one embodiment of the present disclosure comprises:
a multi-shell tank having an inner vessel for accommodating liquid hydrogen, an outer vessel surrounding the inner vessel, and a thermal barrier disposed between the inner vessel and the outer vessel;
a BOG line connected to the inner vessel through which boil-off gas of the liquid hydrogen generated in the inner vessel flows;
A heat exchanger for heating the boil-off gas;
an inter-tank gas supply line for supplying the heated boil-off gas between the inner and outer tanks of the multi-shell tank;
and a compressor that pressure-transfers the heated boil-off gas to the inter-tank gas supply line.

A floating structure according to one embodiment of the present disclosure comprises a hull and the liquid hydrogen storage facility mounted on the hull.

In addition, a method for supplying gas between tanks in a multi-shell tank according to an embodiment of the present disclosure includes the steps of:
1. A method for supplying an inter-vessel gas between an inner and outer vessel in a multi-shell tank having an inner vessel for accommodating liquid hydrogen, an outer vessel surrounding the inner vessel, and a thermal insulation layer disposed between the inner vessel and the outer vessel, comprising:
The boil-off gas of the liquid hydrogen produced in the inner vessel is removed from the inner vessel;
The extracted boil-off gas is heated in a heat exchanger,
The heated boil-off gas is pressure-transported between the inner and outer vessels by a compressor.

According to the present disclosure, in a multi-shell tank having an inner tank that contains liquid hydrogen, an outer tank that surrounds the inner tank, and a thermal insulation layer disposed between the inner and outer tanks, boil-off gas of liquid hydrogen can be supplied between the inner and outer tanks without damaging the thermal insulation layer.

FIG. 1 is a diagram showing a schematic configuration of a liquid hydrogen storage facility according to one embodiment of the present disclosure. FIG. 2 is a diagram showing a liquid hydrogen storage facility according to the first modification. FIG. 3 is a diagram showing a liquid hydrogen storage facility according to the second modification.

Next, an embodiment of the present disclosure will be described with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of a liquid hydrogen storage facility 1 according to one embodiment of the present disclosure. As shown in FIG. 1, the liquid hydrogen storage facility 1 according to one embodiment of the present disclosure includes a multi-shell tank 2 for storing liquid hydrogen, and piping and equipment for receiving liquid hydrogen supplied from outside the liquid hydrogen storage facility 1 into the multi-shell tank 2, storing liquid hydrogen in the multi-shell tank 2, and supplying liquid hydrogen stored in the multi-shell tank 2 to the outside of the liquid hydrogen storage facility 1. The liquid hydrogen storage facility 1 according to this embodiment is installed in the hull 11 of a floating structure 100. The floating structure 100 may include a ship or a floating structure floating on the sea. However, the liquid hydrogen storage facility 1 is not limited to the floating structure 100, and may be installed on land.

The multi-shell tank 2 is connected to a BOG line 3, an inter-tank gas supply line 6, and a cargo liquid line 7. The BOG line 3 is connected in parallel to a cargo gas line 4 and a fuel supply line 5. The cargo gas line 4 and the fuel supply line 5 are gas transport lines that transport boil-off gas B to the outside of the liquid hydrogen storage facility 1. The inter-tank gas supply line 6 is connected in parallel to the cargo gas line 4 and the fuel supply line 5.

The multi-shell tank 2 comprises an inner tank 21 and an outer tank 22 surrounding the inner tank 21. The inner tank 21 and the outer tank 22 are spaced apart in the radial direction of the multi-shell tank 2, and a thermal barrier layer 24 is provided between the inner and outer tanks 23. The thermal barrier layer 24 is not particularly limited, but may be composed of an insulating panel that covers the surface of the inner tank 21, or a thermal insulating material filled between the inner and outer tanks 23.

The inner tank 21 contains cryogenic liquid hydrogen. The space between the inner and outer tanks 23 is filled with boil-off gas of the liquid hydrogen generated in the inner tank 21. The multi-shell tank 2 is equipped with a pressure sensor 25 that detects the pressure between the inner and outer tanks 23.

The loading liquid line 7 is composed of piping that connects the inside of the inner tank 21 to the manifold 8. Liquid hydrogen L flows through the loading liquid line 7, which is supplied to the inner tank 21 from outside the liquid hydrogen storage facility 1 during loading and unloading, and is discharged from the inner tank 21 to the outside. The manifold 8 is the connection between the loading liquid line 7 equipped in the liquid hydrogen storage facility 1 and the piping outside the liquid hydrogen storage facility 1.

The BOG line 3 is connected to the gas phase portion of the inner tank 21 (e.g., the top of the inner tank 21) and is composed of piping extending from the inner tank 21 to the outside of the multi-shell tank 2. Boil-off gas B of liquid hydrogen generated in the inner tank 21 of the multi-shell tank 2 flows out of the BOG line 3. However, the BOG line 3 is not limited to boil-off gas B, and purge gas or cooling gas may also flow. When the liquid hydrogen storage facility 1 is equipped with multiple multi-shell tanks 2, the piping may be configured so that the BOG lines 3 connected to each multi-shell tank 2 merge into a single BOG line 3.

The loading gas line 4 is composed of piping etc. connecting the BOG line 3 and the manifold 8. The loading gas line 4 forcibly sends a part of the boil-off gas B flowing through the BOG line 3 to the outside of the liquid hydrogen storage facility 1 via the manifold 8 during loading etc. The loading gas line 4 may be used to discharge gas from the inner tank 21 for forced cooling or purging of the inner tank 21. The loading gas line 4 is provided with a flow control valve 41 for controlling the flow rate of the boil-off gas B passing through the loading gas line 4, a heat exchanger 42 arranged downstream of the flow control valve 41, and a compressor 43 arranged downstream of the heat exchanger 42. When the heat exchanger 42 and the compressor 43 are operated and the flow control valve 41 is opened, the boil-off gas B flows from the BOG line 3 into the loading gas line 4. The boil-off gas B that flows into the cargo gas line 4 is heated in the heat exchanger 42 and then flows into the compressor 43, which then pressurizes and sends it to the outside via the manifold 8. However, the boil-off gas B that flows into the cargo gas line 4 may also flow into the compressor 43 without passing through the heat exchanger 42 or without being heated by the heat exchanger 42, and then pressurized and sent to the outside via the manifold 8.

The fuel supply line 5 is composed of piping etc. that connects the BOG line 3 and the fuel consuming equipment 9. The fuel supply line 5 sends a portion of the boil-off gas B flowing through the BOG line 3 to the fuel consuming equipment 9 arranged outside the liquid hydrogen storage facility 1. The fuel supply line 5 is provided with a flow control valve 51 that adjusts the flow rate of the boil-off gas B flowing through the fuel supply line 5, a heat exchanger 52 arranged downstream of the flow control valve 51, and a compressor 53 arranged downstream of the heat exchanger 52. When the heat exchanger 52 and the compressor 53 are operating and the flow control valve 51 is opened, the boil-off gas B flows from the BOG line 3 into the fuel supply line 5. The boil-off gas B that flows into the fuel supply line 5 is heated by the heat exchanger 52 and then flows into the compressor 53, where it is pumped to the fuel consuming equipment 9 by the compressor 53. However, the boil-off gas B that flows into the fuel supply line 5 may flow into the compressor 53 without passing through the heat exchanger 52 or being heated by the heat exchanger 52, and may be pumped to the fuel consuming device 9.

The intertank gas supply line 6 is composed of piping etc. that connects the space between the inner and outer tanks 23 of the multi-shell tank 2 to the loading gas line 4 or the fuel supply line 5. The intertank gas supply line 6 supplies a portion of the boil-off gas B flowing through the loading gas line 4 and/or a portion of the boil-off gas B flowing through the fuel supply line 5 to the space between the inner and outer tanks 23 of the intertank gas supply line 6 as intertank gas G. However, the intertank gas supply line 6 is not limited to supplying boil-off gas B to the space between the inner and outer tanks 23, but may also be used to supply purge gas, replacement gas, etc. to the space between the inner and outer tanks 23.

The inter-tank gas supply line 6 includes a main pipe 60 connected to the inner and outer tank gap 23 of the multi-shell tank 2, and a first pipe 61 and a second pipe 62 that connect the loading gas line 4 and the fuel supply line 5 in parallel to the main pipe 60. The first pipe 61 connects the main pipe 60 to the connection part 47 downstream of the compressor 43 of the loading gas line 4. The second pipe 62 connects the main pipe 60 to the connection part 57 downstream of the compressor 53 of the fuel supply line 5. When the liquid hydrogen storage facility 1 has multiple multi-shell tanks 2, a branch pipe is provided that branches from the main pipe 60 to the inner and outer tank gaps 23 of the multiple multi-shell tanks 2, and the inter-tank gas G is supplied to the inner and outer tank gaps 23 of each multi-shell tank 2 through the main pipe 60 and the branch pipe.

The first pipe 61 is provided with a first flow control valve 63 for controlling the flow rate of the boil-off gas B flowing from the cargo handling gas line 4 into the first pipe 61. The first flow control valve 63 is normally closed, and when the first flow control valve 63 is opened, a part of the boil-off gas B flowing through the cargo handling gas line 4 flows into the first pipe 61 (i.e., the inter-tank gas supply line 6). Here, the connection part 47 to which the first pipe 61 is connected is arranged downstream of the heat exchanger 42 of the cargo handling gas line 4, so that the boil-off gas B heated by the heat exchanger 42 flows into the first pipe 61. Note that, although one set of the heat exchanger 42 and the compressor 43 is shown in the cargo handling gas line 4 illustrated in FIG. 1, the cargo handling gas line 4 may be provided with a plurality of heat exchangers 42 and compressors 43. In this case, the connection part 47 may be arranged downstream of at least one heat exchanger 42 or downstream of at least one compressor 43.

As shown in FIG. 2, a temperature regulator 48 may be disposed downstream of the first flow control valve 63 in the first pipe 61. When the temperature of the boil-off gas B does not reach the intertank gas set temperature, which is a suitable temperature for the intertank gas G, when heated by the heat exchanger 42 in the loading gas line 4, the boil-off gas B is heated by this temperature regulator 48 until it reaches the intertank gas set temperature. The intertank gas set temperature is the lowest temperature at which the thermal insulation layer 24 disposed between the inner and outer tanks 23 of the multi-shell tank 2 does not deteriorate. The intertank gas set temperature varies depending on the structure of the multi-shell tank 2 and the type of insulation material constituting the thermal insulation layer 24.

Returning to FIG. 1, the second pipe 62 is provided with a second flow control valve 64 for controlling the flow rate of the boil-off gas B flowing from the fuel supply line 5 into the second pipe 62. The second flow control valve 64 is normally closed, and when the second flow control valve 64 is opened, a part of the boil-off gas B flowing through the fuel supply line 5 flows into the second pipe 62 (i.e., the inter-tank gas supply line 6). Here, the connection part 57 to which the second pipe 62 is connected is disposed downstream of the heat exchanger 52 of the fuel supply line 5, so that the boil-off gas B heated by the heat exchanger 52 flows into the second pipe 62. Note that, although one set of the heat exchanger 52 and the compressor 53 is shown in the fuel supply line 5 illustrated in FIG. 1, the fuel supply line 5 may be provided with a plurality of heat exchangers 52 and compressors 53. In this case, the connection part 57 may be disposed downstream of at least one heat exchanger 52 or downstream of at least one compressor 53.

As shown in FIG. 2, a temperature regulator 58 may be disposed downstream of the second flow control valve 64 in the second piping 62. When the temperature of the boil-off gas B does not reach the inter-tank gas set temperature when heated by the heat exchanger 52 in the fuel supply line 5, the temperature regulator 58 heats the boil-off gas B until it reaches the inter-tank gas set temperature.

Returning to FIG. 1, the flow control valve 41, heat exchanger 42, and compressor 43 of the cargo gas line 4, the flow control valve 51, heat exchanger 52, and compressor 53 of the fuel supply line 5, and the first flow control valve 63 and second flow control valve 64 of the inter-tank gas supply line 6 are arranged in an equipment room 10 provided in the hull 11. The equipment room 10 is a space called the "cargo machinery space" in the classification regulations, and mainly contains cargo equipment. The equipment room 10 is isolated from the living area and work area, and the electrical equipment arranged therein is explosion-proof.

[Method of Supplying Inter-Tank Gas G]
Here, a method of supplying the inter-vessel gas G to the inner and outer vessel gap 23 of the multi-shell tank 2 will be described. The inter-vessel gas G is supplied to the inner and outer vessel gap 23 mainly during initial cooling of the multi-shell tank 2, during loading and unloading, and during the voyage. It is preferable that the inter-vessel pressure between the inner and outer vessels 23 of the multi-shell tank 2 is maintained at a predetermined set inter-vessel pressure while liquid hydrogen is stored in the inner vessel 21. If the inter-vessel pressure falls significantly below the set inter-vessel pressure, the pressure acting on the inner vessel 21 or the pressure acting on the outer vessel 22 becomes excessive, which may lead to damage to the inner vessel 21 or the outer vessel 22. The set inter-vessel pressure differs depending on the configuration of the multi-shell tank 2.

<Initial cooling>
During initial cooling of the multi-shell tank 2, cooling of the inner tank 21 and cooling and pressurization of the space between the inner and outer tanks 23 are performed. During initial cooling, the heat exchanger 42 and compressor 43 of the cargo gas line 4 are operated, the flow control valve 41 of the cargo gas line 4 is opened, the first flow control valve 63 of the intertank gas supply line 6 is opened, and the flow control valve 51 of the fuel supply line 5 and the second flow control valve 64 of the intertank gas supply line 6 are closed. The opening of the first flow control valve 63 is adjusted so that an appropriate amount of intertank gas G for cooling and pressure adjustment is supplied to the space between the inner and outer tanks 23.

When liquid hydrogen L for cooling is supplied to the inner tank 21 from the outside through the loading liquid line 7, part of the liquid hydrogen L vaporizes in the inner tank 21 and becomes boil-off gas B. The boil-off gas B generated in the inner tank 21 flows out to the BOG line 3. The flow control valve 41 is opened, the first flow control valve 63, the flow control valve 51, and the second flow control valve 64 are closed, and as the compressor 43 operates, part of the boil-off gas B is returned to the outside through the loading gas line 4 and the manifold 8. When liquid hydrogen L is supplied to the inner tank 21, the gas between the inner and outer tanks 23 is cooled and the pressure between the inner and outer tanks 23 decreases. Then, the flow control valve 51 and the second flow control valve 64 are opened, the heat exchanger 52 and the compressor 53 are operated, and the remaining boil-off gas B is heated by the heat exchanger 52 of the fuel supply line 5 and then supplied to the space between the inner and outer tanks 23 of the multi-shell tank 2 through the inter-tank gas supply line 6. In this way, the pressure between the inner and outer tanks 23 is restored by the boil-off gas B (i.e., the inter-tank gas G) supplied to the space between the inner and outer tanks 23.

<When preparing for loading and cooling the tank>
When liquid hydrogen L is supplied to the inner tank 21 during preparation for loading liquid hydrogen into the multi-shell tank 2 or when liquid hydrogen is sprayed to cool the tank, the inter-tank gas G in the inner tank 21, the outer tank 22, and the space between the inner and outer tanks 23 is cooled, and the pressure between the inner and outer tanks 23 is reduced. Therefore, the inter-tank gas G is supplied to the space between the inner and outer tanks 23 of the multi-shell tank 2 so that the inter-tank pressure between the inner and outer tanks 23 is maintained at a predetermined set inter-tank pressure. When liquid hydrogen L is loaded into the multi-shell tank 2, the compressor 43 of the loading gas line 4 is operated, the flow control valve 41 of the loading gas line 4 is opened, and the boil-off gas B in the inner tank 21 is forcibly discharged to the outside through the BOG line 3 and the loading gas line 4, so that the inner tank 21 is quickly filled with liquid hydrogen L. When liquid hydrogen L is supplied to the inner tank 21, the gas in the space between the inner and outer tanks 23 is cooled, and the pressure between the inner and outer tanks 23 is reduced. The flow rate control valve 51 of the fuel supply line 5, and the first flow rate control valve 63 and the second flow rate control valve 64 of the intertank gas supply line 6 are normally closed. When the liquid hydrogen L is supplied to the inner tank 21, the inner and outer tank space 23 is cooled, and the intertank pressure detected by the pressure sensor 25 falls below the set intertank pressure, the flow rate control valve 51 and the second flow rate control valve 64 are opened, and the heat exchanger 52 and the compressor 53 are operated. As a result, the intertank gas G, which is a part of the boil-off gas B heated through the fuel supply line 5 and the intertank gas supply line 6, is supplied to the inner and outer tank space 23 of the multi-shell tank 2, and the intertank pressure between the inner and outer tanks 23 of the multi-shell tank 2 is restored to the set intertank pressure. When the intertank pressure is restored to the set intertank pressure, the flow rate control valve 51 and the second flow rate control valve 64 are closed, the heat exchanger 52 and the compressor 53 are stopped, and the supply of the intertank gas G to the inner and outer tank space 23 is stopped.

<On the voyage>
During the voyage, the inter-vessel pressure between the inner and outer vessels 23 of the multi-shell tank 2 may slightly decrease. Therefore, a part of the boil-off gas B flowing through the fuel supply line 5 operating during the voyage is supplied to the inner and outer vessels 23 of the multi-shell tank 2 through the inter-vessel gas supply line 6, so that the inter-vessel pressure is maintained at the set inter-vessel pressure. During the voyage, the heat exchanger 52 and the compressor 53 of the fuel supply line 5 are operated, the flow control valve 51 is opened, and the boil-off gas B of the inner vessel 21 is forcibly sent to the fuel consuming equipment 9 through the BOG line 3 and the fuel supply line 5. The flow control valve 41 of the cargo gas line 4 is closed. The first flow control valve 63 and the second flow control valve 64 of the inter-vessel gas supply line 6 are usually closed. When the intertank pressure detected by the pressure sensor 25 falls below the set intertank pressure, the flow control valve 41 and the first flow control valve 63 are opened, and the heat exchanger 42 and the compressor 43 are operated, so that a part of the boil-off gas B is heated through the loading gas line 4 and the intertank gas supply line 6, and the heated intertank gas G is supplied to the inner and outer tank gap 23 of the multi-shell tank 2. As a result, the intertank pressure between the inner and outer tanks 23 of the multi-shell tank 2 is restored to the set intertank pressure. When the intertank pressure is restored to the set intertank pressure, the flow control valve 41 and the first flow control valve 63 are closed again, the heat exchanger 42 and the compressor 43 are stopped, and the supply of the intertank gas G to the inner and outer tank gap 23 is stopped.

As described above, the inter-tank gas G supplied between the inner and outer tanks 23 is heated by the

heat exchangers

42, 52 and is therefore at a higher temperature than the boil-off gas B in the inner tank 21. Here, the inter-tank gas G supplied between the inner and outer tanks 23 only needs to be at a higher temperature than the boil-off gas B in the inner tank 21 of the multi-shell tank 2, but it is preferable that the boil-off gas B be heated by the

heat exchangers

42, 52 and an additional heat exchanger to a level at which freezing and deterioration of the thermal insulation layer 24 can be suppressed. This makes it possible to suppress freezing and deterioration of the thermal insulation layer 24 arranged between the inner and outer tanks 23.

In the above-mentioned method for supplying inter-tank gas G, the one of the loading gas line 4 and the fuel supply line 5, which is not in operation, is selectively connected to the inter-tank gas supply line 6. This allows the boil-off gas B to be supplied to the space between the inner and outer tanks 23 without impeding the flow of the boil-off gas B in the operating line. In addition, the boil-off gas B can be supplied to the space between the inner and outer tanks 23 at a temperature different from that of the operating line. However, the one of the loading gas line 4 and the fuel supply line 5, which is in operation, may be selectively connected to the inter-tank gas supply line 6. This eliminates the need to start up the

heat exchangers

42, 52 and

compressors

43, 53 just to supply the inter-tank gas G to the space between the inner and outer tanks 23, improving work efficiency.

In the above-mentioned method for supplying inter-tank gas G, the opening/closing and opening adjustment of the

heat exchangers

42, 52,

compressors

43, 53, and each

valve

41, 51, 63, 64 may be performed manually or automatically. For example, when the opening/closing and opening adjustment of the first flow control valve 63 and the second flow control valve 64 are performed automatically, as shown in FIG. 3, the liquid hydrogen storage facility 1 is provided with a controller 26 electrically connected to the pressure sensor 25, the first flow control valve 63, and the second flow control valve 64. When the pressure between the inner and outer tanks 23 detected by the pressure sensor 25 falls below a predetermined set inter-tank pressure, the controller 26 opens/closes and adjusts the opening of the first flow control valve 63 and the second flow control valve 64 so that the boil-off gas B is supplied to the inner and outer tanks 23 until the pressure between the inner and outer tanks 23 reaches the set inter-tank pressure.

[Summary]
The liquid hydrogen storage facility 1 according to the first aspect of the present disclosure comprises:
a multi-shell tank 2 having an inner vessel 21 for accommodating liquid hydrogen, an outer vessel 22 surrounding the inner vessel 21, and a thermal barrier layer 24 disposed in an inner/outer vessel gap 23 between the inner vessel 21 and the outer vessel 22;
a BOG line 3 connected to the inner vessel 21, through which the boil-off gas B of the liquid hydrogen generated in the inner vessel 21 flows;
a

heat exchanger

42, 52 for heating the boil-off gas B;
an inter-vessel gas supply line 6 for supplying the heated boil-off gas B to the space between the inner and outer vessels 23 of the multi-shell tank 2;
and

compressors

43, 53 for compressing and sending the heated boil-off gas B to the inter-tank gas supply line 6.

In the liquid hydrogen storage equipment 1 configured as above, the boil-off gas B of liquid hydrogen generated in the inner tank 21 of the multi-shell tank 2 is not directly supplied to the space between the inner and outer tanks 23, but is heated in the

heat exchangers

42, 52 and then supplied to the space between the inner and outer tanks 23. In this way, the boil-off gas B flowing into the space between the inner and outer tanks 23 is at a higher temperature than the boil-off gas B in the inner tank 21, which prevents the heat insulation layer 24 arranged between the inner and outer tanks 23 from freezing or deteriorating.

The liquid hydrogen storage facility 1 according to the second aspect of the present disclosure is the liquid hydrogen storage facility 1 according to the first aspect,
A gas transport line 4; 5 having a heat exchanger 42; 52 and a compressor 43: 53, and sending the boil-off gas B to the outside of the liquid hydrogen storage facility 1,
A BOG line 3 is connected to the gas transport line 4; 5 upstream of the heat exchanger 42; 52 and the compressor 43: 53,
An inter-tank gas supply line 6 is connected to the gas transport lines 4; 5 downstream of the heat exchangers 42; 52 and compressors 43: 53. In the above, the outside of the liquid hydrogen storage equipment 1 may be equipment other than the liquid hydrogen storage equipment 1 on the ship, for example, in the case where the liquid hydrogen storage equipment 1 is installed on a ship.

In the liquid hydrogen storage equipment 1 configured as above, the

gas transport lines

4 and 5 used to send the boil-off gas B to the outside of the liquid hydrogen storage equipment 1 are also used to supply the inter-tank gas G to the space between the inner and outer tanks 23. Therefore, a dedicated compressor or heat exchanger can be omitted for supplying the inter-tank gas G to the space between the inner and outer tanks 23.

The liquid hydrogen storage equipment 1 according to the third item of the present disclosure is the liquid hydrogen storage equipment 1 according to the second item, in which the gas transport lines 4;5 include a first gas transport line 4 and a second gas transport line 5 connected in parallel to the BOG line 3 and the inter-tank gas supply line 6, and are configured such that when the first gas transport line 4 is connected to the outside and boil-off gas B is sent to the outside through the first gas transport line 4, the second gas transport line 5 is connected to the space between the inner and outer tanks 23 and boil-off gas B is sent to the space between the inner and outer tanks 23 through the second gas transport line 5 and the inter-tank gas supply line 6.

In the liquid hydrogen storage equipment 1 configured as above, while the boil-off gas B is being sent to the outside using the first gas transfer line 4 without being heated, the boil-off gas B can be heated and sent to the space between the inner and outer tanks 23 using the second gas transfer line 5. Alternatively, in the liquid hydrogen storage equipment 1 configured as above, while the boil-off gas B is being heated to a first temperature and sent to the outside using the first gas transfer line 4, the boil-off gas B can be heated to a second temperature and sent to the space between the inner and outer tanks 23 using the second gas transfer line 5.

The liquid hydrogen storage facility 1 according to the fourth item of the present disclosure is the liquid hydrogen storage facility 1 according to the second or third item, in which the gas transport line includes a loading gas line 4 that sends the boil-off gas B to the outside.

In the liquid hydrogen storage facility 1 configured as above, the heat exchanger 42 and compressor 43 of the loading gas line 4 can be used to supply boil-off gas B to the space between the inner and outer tanks 23 of the multi-shell tank 2.

The liquid hydrogen storage equipment 1 according to the fifth item of the present disclosure is the liquid hydrogen storage equipment 1 according to any one of the second to fourth items, in which the gas transport line includes a fuel supply line 5 that sends the boil-off gas B to a fuel consuming device 9.

In the liquid hydrogen storage facility 1 configured as above, the heat exchanger 52 and compressor 53 of the fuel supply line 5 can be used to supply the boil-off gas B to the space between the inner and outer tanks 23 of the multi-shell tank 2.

A liquid hydrogen storage facility 1 according to a sixth aspect of the present disclosure is the liquid hydrogen storage facility 1 according to any one of the first to fifth aspects, wherein the inter-tank gas supply line 6 has

valves

63, 64 for switching between supplying and stopping the boil-off gas B to the space between the inner and outer tanks 23;
a pressure sensor 25 for detecting a pressure between the inner and outer tanks 23 of the multi-shell tank 2;
and a controller 26 which operates the

valves

63, 64 so that the boil-off gas B is supplied to the space between the inner and outer tanks 23 until the pressure between the inner and outer tanks 23 reaches the set inter-tank pressure when the pressure between the inner and outer tanks 23 detected by the pressure sensor 25 falls below a predetermined set inter-tank pressure.

With the liquid hydrogen storage equipment 1 configured as above, the pressure between the inner and outer tanks 23 of the multi-shell tank 2 is automatically maintained at the set inter-tank pressure.

The liquid hydrogen storage equipment 1 according to the seventh item of the present disclosure is a liquid hydrogen storage equipment 1 according to any one of the first to sixth items, in which the inter-tank gas supply line 6 has a

thermostat

48, 58 that adjusts the temperature of the boil-off gas B to a predetermined inter-tank gas set temperature.

With the liquid hydrogen storage equipment 1 configured as above, the inter-tank gas set temperature is adjusted to the inter-tank gas set temperature before being supplied to the space between the inner and outer tanks 23.

The liquid hydrogen storage equipment 1 according to the eighth item of the present disclosure is a liquid hydrogen storage equipment 1 according to any one of the first to seventh items, which has a plurality of multi-shell tanks 2, and the inter-tank gas supply line 6 branches out and is connected to each of the inner and outer tanks 23 of the plurality of multi-shell tanks 2.

With the liquid hydrogen storage equipment 1 configured as described above, inter-tank gas G is supplied from a single inter-tank gas supply line 6 to the inner and outer tanks 23 of multiple multi-shell tanks 2, which reduces the amount of piping and equipment compared to when an inter-tank gas supply line 6 is provided for each of the multi-shell tanks 2.

The floating structure 100 according to the ninth item of the present disclosure comprises a hull 11 and a liquid hydrogen storage facility 1 according to any one of the first to eighth items mounted on the hull 11.

The liquid hydrogen storage facility 1 configured as described above is suitable as a liquid hydrogen storage facility 1 to be mounted on a floating structure 100.

A method for supplying inter-tank gas in a multi-shell tank 2 according to a tenth aspect of the present disclosure is a method for supplying inter-tank gas G to a space between the inner and outer tanks 23 in a multi-shell tank 2 having an inner tank 21 for accommodating liquid hydrogen L, an outer tank 22 surrounding the inner tank 21, and a thermal barrier layer 24 disposed in the space between the inner and outer tanks 23 between the inner tank 21 and the outer tank 22, comprising:
The boil-off gas B of the liquid hydrogen L produced in the inner vessel 21 is taken out from the inner vessel 21,
The extracted boil-off gas B is heated in the

heat exchangers

42 and 52.
The heated boil-off gas B is compressed and fed to the space between the inner and outer vessels 23 by

compressors

43 and 53 .

According to the gas supply method between tanks of the multi-shell tank 2, the boil-off gas B of liquid hydrogen generated in the inner tank 21 of the multi-shell tank 2 is not directly supplied to the tank between the inner and outer tanks 23, but is heated in the

heat exchangers

42, 52 and then supplied to the tank between the inner and outer tanks 23. In this way, the boil-off gas B flowing into the tank between the inner and outer tanks 23 has a higher temperature than the boil-off gas B in the inner tank 21, which prevents the heat insulation layer 24 arranged between the inner and outer tanks 23 from freezing or deteriorating.

The functions of the controller 26 disclosed herein can be performed using circuits or processing circuits including general purpose processors, special purpose processors, integrated circuits, ASICs (Application Specific Integrated Circuits), conventional circuits, and/or combinations thereof configured or programmed to perform the disclosed functions. Processors are considered processing circuits or circuits because they include transistors and other circuitry. In this disclosure, a circuit, unit, or means is hardware that performs the recited functions. The hardware may be hardware disclosed herein or other known hardware that is programmed or configured to perform the recited functions. Where the hardware is a processor, which is considered a type of circuit, the circuit, means, or unit is a combination of hardware and software, and the software is used to configure the hardware and/or the processor.

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

Claims

a multi-shell tank having an inner vessel for accommodating liquid hydrogen, an outer vessel surrounding the inner vessel, and a thermal barrier layer disposed between the inner vessel and the outer vessel;
a BOG line connected to the inner vessel through which boil-off gas of the liquid hydrogen generated in the inner vessel flows;
A heat exchanger for heating the boil-off gas;
an inter-vessel gas supply line for supplying the heated boil-off gas between the inner and outer vessels of the multi-shell tank;
A compressor that pressure-transmits the heated boil-off gas to the inter-tank gas supply line.
Liquid hydrogen storage facility.
a gas transport line having the heat exchanger and the compressor and for sending the boil-off gas to the outside;
The BOG line is connected to the gas transport line upstream of the heat exchanger and the compressor,
The inter-tank gas supply line is connected to the gas transport line downstream of the heat exchanger and the compressor.
2. The liquid hydrogen storage facility according to claim 1.
the gas transport line includes a first gas transport line and a second gas transport line connected in parallel to the BOG line and the inter-tank gas supply line,
when the first gas transport line is connected to the outside and the boil-off gas is sent to the outside through the first gas transport line, the second gas transport line is connected between the inner and outer tanks and the boil-off gas is sent between the inner and outer tanks through the second gas transport line and the inter-tank gas supply line;
3. The liquid hydrogen storage facility according to claim 2.
The gas transport line includes a loading gas line that sends the boil-off gas to the outside.
4. The liquid hydrogen storage facility according to claim 2 or 3.
The gas transport line includes a fuel supply line that delivers the boil-off gas to a fuel consuming device.
5. The liquid hydrogen storage facility according to claim 2.
the inter-tank gas supply line has a valve for switching between supply and stop of the boil-off gas between the inner and outer tanks,
a pressure sensor for detecting a pressure between the inner and outer tanks of the multi-shell tank;
and a controller which operates the valve so that the boil-off gas is supplied between the inner and outer tanks until the pressure between the inner and outer tanks reaches the set inter-tank pressure when the pressure between the inner and outer tanks detected by the pressure sensor falls below a predetermined set inter-tank pressure.
6. The liquid hydrogen storage facility according to claim 1.
The inter-tank gas supply line has a temperature regulator that regulates the temperature of the boil-off gas to a predetermined inter-tank gas set temperature.
7. A liquid hydrogen storage facility according to claim 1.
A plurality of the multi-shell tanks,
The inter-chamber gas supply line is branched and connected to each of the inner and outer chambers of the plurality of multi-shell tanks.
8. A liquid hydrogen storage facility according to any one of claims 1 to 7.
The hull and
and the liquid hydrogen storage facility according to any one of claims 1 to 8, which is mounted on the hull.
Floating structures.
1. A method for supplying an inter-vessel gas between an inner and outer vessel in a multi-shell tank having an inner vessel for accommodating liquid hydrogen, an outer vessel surrounding the inner vessel, and a thermal insulation layer disposed between the inner vessel and the outer vessel, comprising:
The boil-off gas of the liquid hydrogen produced in the inner vessel is removed from the inner vessel;
The extracted boil-off gas is heated in a heat exchanger,
The heated boil-off gas is pressure-transferred between the inner and outer tanks by a compressor.
A method for supplying gas between tanks in a multi-shell tank.