AU2021377024A1

AU2021377024A1 - Floating structure

Info

Publication number: AU2021377024A1
Application number: AU2021377024A
Authority: AU
Inventors: Kazuya Abe; Shinsuke Morimoto
Original assignee: Mitsubishi Shipbuilding Co Ltd
Current assignee: Mitsubishi Shipbuilding Co Ltd
Priority date: 2020-11-12
Filing date: 2021-11-04
Publication date: 2023-06-01
Also published as: EP4215433A4; CN116507550A; KR20230071179A; WO2022102517A1; EP4215433A1; JP2022077598A

Abstract

A floating body comprising: a tank that can selectively store liquefied carbon dioxide and a liquefied gas other than liquefied carbon dioxide; a first safety valve that releases a gas in the tank to the tank exterior as the result of a first pilot valve operating; a first pressure-introducing line that transmits pressure inside of the tank to the first pilot valve; a second safety valve that sends the gas in the tank to the tank exterior as the result of a second pilot valve operating; a vent riser that is disposed at a distance from the second safety valve and releases the gas to the exterior; a connecting conduit that guides the gas sent out by the second safety valve to the vent riser; a second pressure-introducing line that transmits the pressure in the tank to the second pilot valve; and a switching valve that selectively switches the destination to which the pressure in the tank is transmitted between the first pilot valve and the second pilot valve.

Description

DESCRIPTION

Title of Invention

FLOATING STRUCTURE

Technical Field

[0001]

The present disclosure relates to a floating structure.

Priority is claimed on Japanese Patent Application No.

2020-188463, filed on November 12, 2020, the content of

which is incorporated herein by reference.

Background Art

[00021

PTL 1 discloses a configuration in which a tank of an

existing gas transport ship is used for both transporting

liquefied petroleum gas (LPG) and transporting liquefied

carbon dioxide, and a configuration in which the tank of

the existing gas transport ship is used for both

transporting liquefied ammonia gas and transporting

liquefied carbon dioxide.

Citation List

Patent Literature

[00031

[PTL 1] Japanese Unexamined Patent Application

Publication No. 2004-125039

Summary of Invention

Technical Problem

[0004]

The tank configured as described above includes a

safety valve for releasing a pressure inside the tank to an

outside of the tank when the pressure inside the tank

exceeds a design pressure.

When a flammable liquefied gas such as the liquefied

petroleum gas is stored in the tank, the safety valve is

connected to a vent riser via a pipe. When the safety valve

is opened to discharge gaseous liquefied gas in the tank,

the gaseous liquefied gas is not directly discharged to an

atmosphere from a discharge port of the safety valve, and

is guided to the vent riser from the safety valve through

the pipe. The gaseous liquefied gas is discharged to the

atmosphere from an outlet of the vent riser disposed at a

high place.

[00051

On the other hand, when the liquefied carbon dioxide

is stored inside the tank, the safety valve is opened, and

gaseous carbon dioxide in which the liquefied carbon dioxide

is vaporized is discharged to the outside of the tank.

Since a pressure outside the tank is an atmospheric pressure,

a pressure of the carbon dioxide is lowered. Due to the

lowered pressure, there is a possibility that the carbon dioxide may be solidified to generate dry ice. When a pipe to the vent riser is connected to the discharge port of the safety valve, there is a possibility that the pipe may be internally blocked due to the generated dry ice.

[00061

That is, when the tank in which both the liquefied

carbon dioxide and the liquefied gas other than liquefied

carbon dioxide can be selected as a storage object, in

accordance with the storage object, it is necessary to carry

out work for switching a discharge destination by

independently installing the safety valve for the liquefied

carbon dioxide and the safety valve for the liquefied gas.

However, when the discharge destination of the storage

object is incorrect, there is a possibility that a

disadvantage such as blockage inside the pipe may arise.

Therefore, it is necessary to pay close attention to the

discharge destination when the discharge destination of the

storage object is switched. Consequently, there is a

problem in that a burden on an operator may increase.

[0007]

The present disclosure is made to solve the above

described problems, and an object of the present disclosure

is to provide a floating structure which can easily and

safely switching a discharge destination of a tank storage

object to be discharged from a safety valve.

Solution to Problem

[00081

According to the present disclosure, in order to solve

the above-described problems, there is provided a floating

structure including a floating main structure, a tank, a

first safety valve, a first pressure introduction line, a

second safety valve, a vent riser, a connection pipe, a

second pressure introduction line, and a switching valve.

The tank is disposed in the floating main structure. The

tank can selectively store liquefied carbon dioxide and

liquefied gas other than liquefied carbon dioxide. The

first safety valve includes a first pilot valve operated

when a pressure inside the tank reaches a predetermined set

pressure. The first safety valve discharges gas inside the

tank to an outside of the tank by operating the first pilot

valve. The first pressure introduction line transmits the

pressure inside the tank to the first pilot valve. The

second safety valve includes a second pilot valve operated

when the pressure inside the tank reaches a predetermined

set pressure. The second safety valve feeds the gas inside

the tank to the outside of the tank by operating the second

pilot valve. The vent riser is disposed apart from the

second safety valve. The vent riser discharges the gas to

the outside. The connection pipe connects the second safety

valve and the vent riser. The connection pipe guides the gas fed from the second safety valve to the vent riser. The second pressure introduction line transmits the pressure inside the tank to the second pilot valve. The switching valve selectively switches a transmission destination of the pressure inside the tank between the first pilot valve and the second pilot valve.

[0009]

According to the present disclosure, there is provided

a floating structure including a floating main structure, a

tank, a safety valve, a vent riser, and a connection pipe.

The tank is disposed in the floating main structure. The

tank can selectively store liquefied carbon dioxide and

liquefied gas other than liquefied carbon dioxide. The

safety valve discharges the gas inside the tank to the

outside of the tank when a pressure inside the tank reaches

a predetermined set pressure. The vent riser is disposed

apart from the safety valve. The vent riser discharges the

gas to the outside. The connection pipe connects the safety

valve and the vent riser. The connection pipe includes a

detachable pipe and a connection pipe main body. The

detachable pipe forms a portion of the connection pipe in

an extending direction of the connection pipe. The

connection pipe main body forms a remaining portion of the

connection pipe. The detachable pipe is configured to be

detached from the connection pipe main body.

Advantageous Effects of Invention

[0010]

According to the floating structure of the present

disclosure, it is possible to easily and safely switch a

discharge destination of a tank storage object discharged

from the safety valve.

Brief Description of Drawings

[0011]

Fig. 1 is a plan view illustrating a schematic

configuration of a ship serving as a floating structure

according to an embodiment of the present disclosure.

Fig. 2 is a view illustrating a tank and a safety valve

system which are provided in the ship according to the

embodiment of the present disclosure, and is a sectional

view taken along line II-II in Fig. 1.

Fig. 3 is a sectional view illustrating a schematic

configuration of a first safety valve and a second safety

valve of a safety valve system according to a first

embodiment of the present disclosure.

Fig. 4 is a view illustrating a state where liquefied

carbon dioxide is stored in a tank in the safety valve

system according to the first embodiment of the present

disclosure.

Fig. 5 is a view illustrating a state where liquefied

gas is stored in the tank in the safety valve system according to the first embodiment of the present disclosure.

Fig. 6 is a view illustrating a state where liquefied

gas is stored in a tank in a safety valve system according

to a modification example of the first embodiment of the

present disclosure.

Fig. 7 is a view illustrating a state where liquefied

carbon dioxide is stored in the tank in the safety valve

system according to the modification example of the first

embodiment of the present disclosure.

Fig. 8 is a view illustrating a state where liquefied

gas is stored in a tank in a safety valve system according

to a second embodiment of the present disclosure.

Fig. 9 is a view illustrating a state where liquefied

carbon dioxide is stored in the tank in the safety valve

system according to the second embodiment of the present

disclosure.

Description of Embodiments

[00121

Hereinafter, a floating structure according to an

embodiment of the present disclosure will be described with

reference to Figs. 1 to 9.

(Configuration of Ship)

As illustrated in Fig. 1, in this embodiment, a ship

1A as a floating structure includes at least a hull 2 as a floating main structure and a tank facility 10.

[00131

(Configuration of Hull)

The hull 2 has a pair of broadsides 3A and 3B, a ship

bottom (not illustrated), and an upper deck 5 which form an

outer shell thereof. The broadsides 3A and 3B have a pair

of broadside skins each forming right and left broadsides.

The ship bottom (not illustrated) has a ship bottom skin

connecting the broadsides 3A and 3B. The pair of broadsides

3A and 3B and the ship bottom (not illustrated) cause the

outer shell of the hull 2 to have a U-shape in a cross

section orthogonal to a bow-stern direction Da. The upper

deck 5 described as an example in this embodiment is a whole

deck exposed outward. In the hull 2, a superstructure 7

having an accommodation space is formed on the upper deck 5

on a stern 2b side. A position of the superstructure 7 is

merely an example, and may be disposed on a bow 2a side of

the hull 2, for example.

[0014]

A cargo tank storage compartment (hold) 8 is formed

inside the hull 2.

A vent riser 9 (to be described later) is disposed on

the upper deck 5 of the hull 2. Disposition of the vent

riser 9 is merely an example, and safety valve connection

pipes of a plurality of the tanks 11 may be connected to one vent riser 9.

[00151

(Configuration of Tank Facility)

A plurality of the tank facilities 10 are disposed

inside the cargo tank storage compartment 8 along the bow

stern direction Da. In this embodiment, two tank facilities

are disposed at an interval in the bow-stern direction

Da.

[00161

As illustrated in Fig. 2, the tank facility 10 includes

at least the tank 11, a loading pipe 13, a unloading pipe

14, and a safety valve system 20A.

In this embodiment, the tank 11 is disposed in the

hull 2. For example, the tank 11 has a cylindrical shape

extending in a horizontal direction. The tank 11 is not

limited to the cylindrical shape, and the tank 11 may have

a spherical shape or a square shape.

[0017]

The tank 11 can selectively store liquefied carbon

dioxide Li and liquefied gas L2 other than the liquefied

carbon dioxide Li inside the tank 11. For example, the

liquefied gas L2 other than the liquefied carbon dioxide Li

includes liquefied petroleum gas (LPG), liquefied natural

gas (LNG), and ammonia. In the following description, the

liquefied carbon dioxide Li and the liquefied gas L2 which are stored inside the tank 11 may be simply referred to as a stored gas L, except when the liquefied carbon dioxide Li and the liquefied gas L2 need to be distinguished from each other.

[0018]

The loading pipe 13 loads the stored gas L supplied

from an onshore facility into the tank 11. The loading pipe

13 penetrates a top portion of the tank 11 from an outside

of the tank 11, and extends to the inside of the tank 11.

A tip portion of the loading pipe 13 is open inside the tank

11.

[0019]

The unloading pipe 14 feeds the stored gas L inside

the tank 11 to the outside of the ship. The unloading pipe

14 penetrates the top portion of the tank 11 from the outside

of the tank 11, and extends to the inside of the tank 11.

A pump (not illustrated) is provided in a tip portion of

the unloading pipe 14. The pump suctions the stored gas L

inside the tank 11. The unloading pipe 14 feeds the stored

gas L suctioned by the pump to the outside of the tank 11

(outside of the ship)

[00201

(Configuration of Safety Valve System)

The safety valve system 20A mainly includes a first

safety valve 21, a second safety valve 31, a connection pipe

, a vent riser 9, a first pressure introduction line 41,

a second pressure introduction line 42, and a switching

valve 43.

[00211

The first safety valve 21 is disposed in the top

portion of the tank 11. The first safety valve 21 is

configured to function when the liquefied carbon dioxide Li

is stored inside the tank 11. The first safety valve 21

releases a pressure inside the tank 11 when a gas phase

(gaseous) pressure inside the tank 11 reaches a

predetermined set pressure. As illustrated in Fig. 3, the

first safety valve 21 is a so-called pilot type, and

includes a main valve 22 and a first pilot valve 23.

[00221

The main valve 22 is disposed inside a main valve valve

casing 24. An inflow port 24a and a discharge port 24b are

formed in the main valve valve casing 24. The inflow port

24a communicates with the inside of the tank 11. The

discharge port 24b is open toward the outside of the tank

11. That is, the discharge port 24b is open to an atmosphere.

The main valve 22 is configured to be connectable to and

detachable from the inflow port 24a. When the main valve

22 closes the inflow port 24a, the first safety valve 21 is

brought into a blocked state. The pressure inside the tank

11 acts on the main valve 22 from the inflow port 24a side.

The main valve valve casing 24 includes a back pressure

chamber 24d on a side opposite to the inflow port 24a side

with respect to the main valve 22.

[00231

The first pilot valve 23 applies a pilot pressure for

biasing the main valve 22 in a closing direction. The first

pilot valve 23 includes a tubular cylinder 25, a valve body

26, and a biasing member 27.

The valve body 26 is disposed to be capable of

reciprocating inside the cylinder 25. The biasing member

27 is disposed on one side in a direction in which the

biasing member 27 reciprocates with respect to the valve

body 26. The biasing member 27 biases the valve body 26 to

the other side inside the cylinder 25. A pressure

introduction chamber 25s is formed on the other side (side

opposite to the biasing member 27) with respect to the valve

body 26 inside the cylinder 25. The pressure inside the

tank 11 is transmitted to the pressure introduction chamber

s through a first pressure introduction line 41 (to be

described later). In other words, the pressure introduction

chamber 25s can communicate with the inside of the tank 11

via the first pressure introduction line 41, and is

configured so that the inside of the pressure introduction

chamber 25s and a gas phase inside the tank 11 have the same

pressure when communicating with the inside of the tank 11.

The pressure introduction chamber 25s and the back pressure

chamber 24d of the main valve valve casing 24 are connected

to communicate with each other via a communication line 28.

[00241

The valve body 26 of the first pilot valve 23

configured in this way is normally biased to the pressure

introduction chamber 25s side by the biasing member 27.

When the pressure inside the tank 11 increases, the pressure

inside the pressure introduction chamber 25s also increases

in response thereto. When the pressure inside the pressure

introduction chamber 25s exceeds a biasing force of the

biasing member 27, the valve body 26 moves inside the

cylinder 25 against the biasing force of the biasing member

27. When the pressure inside the pressure introduction

chamber 25s reaches a predetermined set pressure, for

example, the inside of the pressure introduction chamber

s is released to the atmosphere, and the pressure inside

the pressure introduction chamber 25s decreases. The

pressure decrease inside the pressure introduction chamber

s is transmitted to the back pressure chamber 24d through

the communication line 28. In this manner, a pressure

difference is generated between the inflow port 24a side

and the back pressure chamber 24d side while the main valve

22 is interposed therebetween, and the main valve 22 moves

in a direction apart from the inflow port 24a. In this manner, the first safety valve 21 is brought into an opened state, and the inflow port 24a and the discharge port 24b communicate with each other. In this case, vaporized gas

(gas) of the liquefied carbon dioxide Li inside the tank 11

is discharged from the discharge port 24b.

[00251

The second safety valve 31 is disposed in the top

portion of the tank 11. The second safety valve 31 is

configured to function when the liquefied gas L2 is stored

inside the tank 11. The second safety valve 31 releases

the pressure inside the tank 11 when the pressure in a gas

phase inside the tank 11 reaches a predetermined set

pressure. The second safety valve 31 includes a main valve

32 having the same structure as the first safety valve 21,

and a second pilot valve 33.

[00261

The main valve 32 is disposed inside the main valve

valve casing 34. An inflow port 34a and a discharge port

34b are formed in the main valve valve casing 34. The

inflow port 34a communicates with the inside of the tank 11.

As illustrated in Fig. 2, a connection pipe 45 (to be

described later) is connected to the discharge port 34b.

The main valve 32 is configured to be connectable to and

detachable from the inflow port 34a. When the main valve

32 closes the inflow port 34a, the second safety valve 31 is brought into a blocked state. The pressure inside the tank 11 acts on the main valve 32 from the inflow port 34a side. The main valve valve casing 34 includes a back pressure chamber 34d on a side opposite to the inflow port

34a side with respect to the main valve 32.

[0027]

The second pilot valve 33 applies a pilot pressure for

biasing the main valve 32 in a closing direction. The

second pilot valve 33 has the same configuration as the

first pilot valve 23, and includes a tubular cylinder 35, a

valve body 36, and a biasing member 37.

The valve body 36 is disposed to be capable of

reciprocating inside the cylinder 35. The biasing member

37 is disposed on one side in a direction in which the

biasing member 37 reciprocates with respect to the valve

body 36. The biasing member 37 biases the valve body 36 to

the other side inside the cylinder 35. A pressure

introduction chamber 35s is formed on the other side (side

opposite to the biasing member 37) with respect to the valve

body 36 inside the cylinder 35. The pressure inside the

tank 11 is transmitted to the pressure introduction chamber

s through a second pressure introduction line 42 (to be

described later). In other words, the pressure introduction

chamber 35s can communicate with the inside of the tank 11

via the second pressure introduction line 42, and is configured so that the inside of the pressure introduction chamber 35s and a gas phase inside the tank 11 have the same pressure when communicating with the inside of the tank 11.

The pressure introduction chamber 35s and the back pressure

chamber 34d are connected to communicate with each other

via a communication line 38.

[00281

As in the valve body 26 of the first pilot valve 23,

the valve body 36 of the second pilot valve 33 is normally

biased to the pressure introduction chamber 35s side by the

biasing member 37. When the pressure inside the tank 11

increases, the pressure inside the pressure introduction

chamber 35s also increases in response thereto. When the

pressure inside the pressure introduction chamber 35s

exceeds the biasing force of the biasing member 37, the

valve body 36 moves inside the cylinder 35 against the

biasing force of the biasing member 37. When the pressure

inside the pressure introduction chamber 35s reaches a

predetermined set pressure, for example, the inside of the

pressure introduction chamber 35s is released to the

atmosphere, and the pressure inside the pressure

introduction chamber 35s decreases. The pressure decrease

inside the pressure introduction chamber 35s is transmitted

to the back pressure chamber 34d through the communication

line 38. In this manner, a pressure difference is generated between the inflow port 34a side and the back pressure chamber 34d side while the main valve 32 is interposed therebetween, and the main valve 32 moves in a direction apart from the inflow port 34a. In this manner, the second safety valve 31 is brought into an opened state, and the inflow port 34a and the discharge port 34b communicate with each other. In this case, vaporized gas (gas) of the liquefied gas L2 inside the tank 11 is fed to the connection pipe 45 from the discharge port 34b.

[00291

As illustrated in Fig. 2, the vent riser 9 is connected

to the second safety valve 31. More specifically, the vent

riser 9 is connected to the second safety valve 31 via the

connection pipe 45. The vent riser 9 is disposed apart from

the second safety valve 31, and discharges the vaporized

gas of the liquefied gas L2 fed from the second safety valve

31 to the outside (in other words, the atmosphere). The

connection pipe 45 connects the second safety valve 31 and

the vent riser 9, and guides the gas fed from the discharge

port 34b of the second safety valve 31 to the vent riser 9.

[00301

The first pressure introduction line 41 is a pipe for

transmitting the pressure inside the tank 11 to the first

pilot valve 23. The second pressure introduction line 42

is a pipe for transmitting the pressure inside the tank 11 to the second pilot valve 33. The first pressure introduction line 41 and the second pressure introduction line 42 are connected to the tank 11 via the switching valve

43. The switching valve 43 in this embodiment is connected

to the tank 11 via a pressure supply pipe 44. The switching

valve 43 is a so-called three-way valve, and can communicate

with the pressure supply pipe 44 by selecting one of the

first pressure introduction line 41 and the second pressure

introduction line 42. The switching valve 43 causes the

gas phase inside the tank 11 to communicate with the first

pressure introduction line 41 or the second pressure

introduction line 42 through the pressure supply pipe 44.

In this way, the switching valve 43 can selectively switch

a transmission destination of the pressure inside the tank

11 between the first pilot valve 23 and the second pilot

valve 33.

[00311

As illustrated in Fig. 4, when the liquefied carbon

dioxide Li is stored inside the tank 11, the switching valve

43 causes the first pressure introduction line 41 on the

first safety valve 21 side and the gas phase inside the tank

11 to communicate with each other. On the other hand, as

illustrated in Fig. 5, when the liquefied gas L2 is stored

inside the tank 11, the switching valve 43 causes the second

pressure introduction line 42 on the second safety valve 31 side and the gas phase inside the tank 11 to communicate with each other. A switching operation of the switching valve 43 may be manually performed by an operator, or may be automatically performed.

[00321

The switching valve 43 includes a detection unit 43s

that detects a transmission destination of the pressure

inside the tank 11. The detection unit 43s has a limit

switch that detects a switching state of a switching switch

of the switching valve 43. An information output unit 43m

that outputs information indicating the transmission

destination of the pressure detected by the detection unit

43s to the outside is connected to the switching valve 43.

For example, the information indicating the transmission

destination of the pressure detected by the detection unit

43s indicates whether the transmission destination of the

pressure is the first safety valve 21 side or the second

safety valve 31 side. For example, the information output

unit 43m can output the information indicating the

transmission destination of the pressure by lighting a lamp

indicating the transmission destination of the pressure or

displaying character information indicating the

transmission destination of the pressure.

[00331

(Operational Effect)

In the ship 1A of the above-described embodiment, when

the liquefied carbon dioxide Li is stored in the tank 11,

the first safety valve 21 is caused to function. The first

safety valve 21 functions by transmitting the pressure

inside the tank 11 to the first pilot valve 23 through the

first pressure introduction line 41. When the pressure in

the gas phase inside the tank 11 reaches a predetermined

set pressure, the first pilot valve 23 is operated. When

the first pilot valve 23 is operated, the gas inside the

tank 11 (gas of the liquefied carbon dioxide LI) is

discharged to the outside of the tank 11 by the first safety

valve 21.

[00341

On the other hand, when the liquefied gas L2 other

than the liquefied carbon dioxide Li is stored in the tank

11, the second safety valve 31 is caused to function. The

second safety valve 31 functions by transmitting the

pressure inside the tank 11 to the second pilot valve 33

through the second pressure introduction line 42. When the

pressure in the gas phase inside the tank 11 reaches a

predetermined set pressure, the second pilot valve 33 is

operated. When the second pilot valve 33 is operated, the

second safety valve 31 feeds the gas inside the tank 11

(vaporized gas of the liquefied gas L2) to the outside of

the tank 11. The gas fed from the tank 11 is fed to the vent riser 9 through the connection pipe 45. Thereafter, the gas guided to the vent riser 9 is discharged to the outside from the vent riser 9.

[00351

In this way, the vaporized gas of the liquefied gas L2

is discharged from the vent riser 9 disposed apart from the

second safety valve 31. In contrast, the vaporized gas of

the liquefied carbon dioxide Li is directly discharged from

the first safety valve 21. Unlike the second safety valve

31, the first safety valve 21 is not connected to the

connection pipe 45 and the vent riser 9. Therefore, even

in a case where the dry ice is generated when the liquefied

carbon dioxide Li discharges the vaporized gas in the first

safety valve 21, it is possible to prevent the connection

pipe 45 from being blocked due to the generated dry ice.

[00361

Furthermore, the switching valve 43 can selectively

switch the transmission destination of the pressure inside

the tank 11 between the first pilot valve 23 and the second

pilot valve 33. That is, the switching valve 43 may be

switched as follows. When the liquefied carbon dioxide Li

is stored in the tank 11, the pressure inside the tank 11

is transmitted to the first safety valve 21, and when the

liquefied gas L2 is stored, the pressure inside the tank 11

is transmitted to the second safety valve 31. In this manner, a proper safety valve (first safety valve 21 or second safety valve 31) can be selected to function in accordance with a storage object to be stored in the tank

11. Therefore, the discharge destination of the storage

object in the tank 11 can be easily and safely switched.

[0037]

In addition, in the ship 1A of the above-described

embodiment, the information indicating the transmission

destination of the pressure inside the tank 11 in the

switching valve 43 which is detected by the detection unit

43s is output to the outside by the information output unit

43m. Therefore, an operator can easily recognize the

transmission destination of the pressure inside the tank 11

in the switching valve 43, based on the information output

from the information output unit 43m. That is, when a type

of the storage object stored inside the tank 11 and the

safety valve functioning by transmitting the pressure inside

the tank 11 are different, the operator can easily recognize

and deal with the difference.

[00381

(Modification Example of First Embodiment)

In the above-described embodiment, configurations may

be provided as follows.

As illustrated in Figs. 6 and 7, the connection pipe

includes a detachable pipe 49 forming a portion of the connection pipe 45 and a connection pipe main body 48 forming a remaining portion of the connection pipe 45 excluding the detachable pipe 49. The detachable pipe 49 forms the portion of the connection pipe 45 in an extending direction of the connection pipe 45. The detachable pipe

49 is configured to be detached from the connection pipe

main body 48. The detachable pipe 49 in this modification

example is disposed on a side close to the second safety

valve 31 in the connection pipe 45. More specifically, the

detachable pipe 49 is attached so that the connection pipe

main body 48 serving as the remaining portion of the

connection pipe 45 and the second safety valve 31 can

communicate with each other, and is flange-connected to the

connection pipe main body 48, for example. According to

this configuration, as illustrated in Fig. 6, the detachable

pipe 49 is normally mounted as a portion of the connection

pipe 45. In this manner, as in the above-described

embodiment, when the second safety valve 31 is caused to

function in a case where the liquefied gas L2 is stored

inside the tank 11, the vaporized gas of the liquefied gas

L2 is guided from the second safety valve 31 to the vent

riser 9, and is discharged to the outside through the

connection pipe 45.

[00391

In this configuration, for example, in a state where the liquefied carbon dioxide Li is stored inside the tank

11, when the first safety valve 21 does not normally

function for some reason, as illustrated in Fig. 7, the

detachable pipe 49 is detached from the connection pipe 45.

In this manner, the discharge port 34b of the second safety

valve 31 is opened to the atmosphere, and the gas discharged

from the discharge port 34b is brought into a state where

the gas can be immediately discharged to the atmosphere.

In the switching valve 43, even in a state where the

liquefied carbon dioxide Li is stored inside the tank 11,

the transmission destination of the pressure inside the tank

11 is set to the second pressure introduction line 42 on

the second safety valve 31 side. In this manner, when the

second safety valve 31 functions, the pressure inside the

tank 11 increases, and exceeds a predetermined set pressure,

the vaporized gas of the liquefied carbon dioxide Li inside

the tank 11 can be discharged to the outside (atmosphere)

via the second safety valve 31.

[0040]

In this case, the detachable pipe 49 is in a detached

state in preparation for a case where the dry ice is

generated by the gas of the carbon dioxide discharged from

the second safety valve 31. Therefore, the discharge port

34b of the second safety valve 31 is brought into a state

close to a case where the discharge port 34b is directly opened to the atmosphere. In this manner, even when the dry ice is generated by the gas of the carbon dioxide discharged from the discharge port 34b during an operation of the second safety valve 31, it is possible to prevent the connection pipe 45 from being blocked due to the generated dry ice.

[00411

In the above-described modification example, the

detachable pipe 49 is disposed on the side close to the

second safety valve 31 in the connection pipe 45. However,

the present disclosure is not limited thereto. The

detachable pipe 49 may be disposed at any position in the

connection pipe 45.

[00421

Next, a second embodiment of the floating structure

according to the present invention will be described. The

second embodiment described below is different from the

first embodiment in only a configuration of a safety valve

system. Therefore, description will be made by assigning

the same reference numerals to elements which are the same

as those of the first embodiment, and repeated description

will be omitted.

As illustrated in Fig. 8, in the second embodiment, a

ship 1B as a floating structure includes at least a safety valve system 20B in the tank facility 10.

[00431

In the second embodiment, the tank 11 can selectively

store the liquefied carbon dioxide Li and the liquefied gas

L2 other than the liquefied carbon dioxide Li inside the

tank 11. For example, the liquefied gas L2 other than the

liquefied carbon dioxide Li includes liquefied petroleum

gas (LPG), liquefied natural gas (LNG), and ammonia.

[0044]

The loading pipe 13 loads the stored gas L supplied

from an onshore facility into the tank 11. The loading pipe

13 penetrates a top portion of the tank 11 from an outside

of the tank 11, and extends to the inside of the tank 11.

A tip portion of the loading pipe 13 is open inside the tank

11.

[00451

The unloading pipe 14 feeds the stored gas L inside

the tank 11 to the outside of the ship. The unloading pipe

14 penetrates the top portion of the tank 11 from the outside

of the tank 11, and extends to the inside of the tank 11.

A pump (not illustrated) is provided in a tip portion of

the unloading pipe 14. The pump suctions the stored gas L

inside the tank 11. The unloading pipe 14 feeds the stored

gas L suctioned by the pump to the outside of the tank 11

(outside of the ship).

[00461

(Configuration of Safety Valve System)

The safety valve system 20B mainly includes a safety

valve 51, a connection pipe 55, and the vent riser 9.

[00471

The safety valve 51 is disposed in the top portion of

the tank 11. The safety valve 51 releases the pressure

inside the tank 11 when the pressure of the stored gas L

inside the tank 11 reaches a predetermined set pressure.

The safety valve 51 may be of a pilot type as in the first

embodiment.

[00481

The vent riser 9 is disposed apart from the safety

valve 51. The vent riser 9 discharges the vaporized gas of

the liquefied gas L2 fed from the safety valve 51 to the

outside. The vent riser 9 is connected to the safety valve

51 via the connection pipe 55.

[0049]

The connection pipe 55 connects the safety valve 51

and the vent riser 9. The connection pipe 55 is connected

to a discharge port 54b of the safety valve 51. The

connection pipe 55 partially includes a detachable pipe 59

which is detachable. As in the detachable pipe 49 of the

first embodiment, the detachable pipe 59 is flange-connected

to a connection pipe main body 58 which is a remaining portion of the connection pipe 55. In addition, the detachable pipe 59 of the second embodiment is disposed between the connection pipe main body 58 and the safety valve 51 on a side close to the safety valve 51 in the connection pipe 55. The detachable pipe 59 may be disposed at any position in the connection pipe 55 without being limited to the side close to the safety valve 51.

[00501

In this safety valve system 20B, when the liquefied

gas L2 is stored inside the tank 11, the detachable pipe 59

is connected as a portion of the connection pipe 55. When

the safety valve 51 is operated to discharge the vaporized

gas of the liquefied gas L2 inside the tank 11 to the outside,

the vaporized gas of the liquefied gas L2 is guided from

the safety valve 51 to the vent riser 9, and is discharged

to the outside through the connection pipe 55.

[00511

On the other hand, as illustrated in Fig. 9, when the

liquefied carbon dioxide Li is stored inside the tank 11,

the detachable pipe 59 is detached from the connection pipe

55. In this case, the connection pipe 55 is disposed between

the safety valve 51 and the connection pipe main body 58.

Therefore, in a state where the detachable pipe 59 is

detached, the discharge port 54b of the safety valve 51 is

brought into a state close to a case where the discharge port 54b is directly opened to the atmosphere.

[00521

Therefore, even when the pressure inside the tank 11

increases, exceeds a predetermined set pressure, the safety

valve 51 is operated, the vaporized gas of the liquefied

carbon dioxide Li inside the tank 11 is discharged from the

discharge port 54b due to the gas of the carbon dioxide,

and the dry ice is generated, it is possible to prevent the

connection pipe 55 from being blocked due to the generated

dry ice.

[00531

(Operational Effect)

According to the ship 1B of the second embodiment

described above, when the liquefied carbon dioxide Li is

stored in the tank 11, the detachable pipe 59 which is a

portion of the connection pipe 55 is detached. In this

manner, the discharge port 54b of the safety valve 51 can

be opened to the atmosphere at a position close to the

discharge port 54b of the safety valve 51. Accordingly,

even when the dry ice is generated by the gas of the carbon

dioxide discharged from the discharge port 54b during the

operation of the safety valve 51, it is possible to prevent

the connection pipe 55 from being blocked due to the

generated dry ice. In addition, when the liquefied gas L2

is stored in the tank 11, the vaporized gas of the liquefied gas L2 fed from the safety valve 51 during the operation of the safety valve 51 can be guided to the vent riser 9 and discharged to the outside through the connection pipe 55.

In this way, while the safety valve 51 is used for

both the liquefied carbon dioxide Li and the liquefied gas

L2, the detachable pipe 59 is simply attached and detached

in accordance with a type of the storage object to be stored

in the tank 11. In this manner, a discharge form from the

safety valve 51 can be properly selected. The operator can

easily recognize that the detachable pipe 59 is in a

detached state. Therefore, the discharge destination of

the storage object in the tank 11 to be discharged from the

safety valve 51 can be easily and safely switched. In

addition, since the safety valve 51 can be used for both

the liquefied carbon dioxide Li and the liquefied gas L2,

costs for the facility can be reduced.

[0054]

(Other Embodiments)

Hitherto, the embodiments of the present disclosure

have been described in detail with reference to the drawings.

However, specific configurations are not limited to the

above-described embodiments, and design changes within the

scope not departing from the concept of the present

disclosure are also included.

For example, in the above-described embodiment, the first safety valve 21, the second safety valve 31, and the safety valve 51 are provided one by one. However, the present disclosure is not limited thereto. A plurality of the first safety valves 21, the second safety valves 31, and the safety valves 51 may be respectively provided. When the plurality of first safety valves 21, second safety valves 31, and safety valves 51 are provided, the set pressures of the first safety valve 21, the second safety valve 31, and the safety valve 51 may be differently changed in a stepwise manner.

[00551

In the above-described embodiment, a configuration

including two tanks 11 has been adopted. However, the

present disclosure is not limited thereto. The

configuration may include one, three, or more tanks 11.

In addition, in the above-described embodiment, the

ships 1A and 1B have been described as examples of the

floating structure. However, the present disclosure is not

limited thereto. The floating structure may be an offshore

floating structure facility which does not include a

propulsion mechanism.

[00561

The floating structures 1A and 1B described in the

respective embodiments can be understood as follows, for example.

[0057]

(1) According to a first aspect, there are provided

the floating structures 1A and 1B including the floating

main structure 2, the tank 11 disposed in the floating main

structure 2 to selectively store the liquefied carbon

dioxide Li and the liquefied gas L2 other than the liquefied

carbon dioxide LI, the first safety valve 21 having the

first pilot valve 23 operated when the pressure inside the

tank 11 reaches a predetermined set pressure and discharging

the gas inside the tank 11 to the outside of the tank 11 by

operating the first pilot valve 23, the first pressure

introduction line 41 transmitting the pressure inside the

tank 11 to the first pilot valve 23, the second safety valve

31 having the second pilot valve 33 operated when the

pressure inside the tank 11 reaches a predetermined set

pressure and feeding the gas inside the tank 11 to the

outside of the tank 11 by operating the second pilot valve

33, the vent riser 9 disposed apart from the second safety

valve 31 and discharging the gas to the outside, the

connection pipe 45 connecting the second safety valve 31

and the vent riser 9 to guide the gas fed from the second

safety valve 31 to the vent riser 9, the second pressure

introduction line 42 transmitting the pressure inside the

tank 11 to the second pilot valve 33, and the switching valve 43 selectively switching the transmission destination of the pressure inside the tank 11 between the first pilot valve 23 and the second pilot valve 33.

Examples of the floating structures 1A and 1B include

the ship and an offshore floating structure facility.

Examples of the floating main structure 2 include the hull

and the floating main structure 2 of the offshore floating

structure facility.

Examples of the liquefied gas L2 include liquefied

petroleum gas, liquefied natural gas, and ammonia.

[00581

The floating structures 1A and 1B cause the first

safety valve 21 to function when the liquefied carbon

dioxide Li is stored in the tank 11. The first safety valve

21 functions by transmitting the pressure inside the tank

11 to the first pilot valve 23 through the first pressure

introduction line 41. When the pressure inside the tank 11

reaches the set pressure, the first pilot valve 23 is

operated. When the first pilot valve 23 is operated, the

gas inside the tank 11 (vaporized gas of the liquefied

carbon dioxide Li) can be discharged to the outside of the

tank 11 by the first safety valve 21.

When the liquefied gas L2 other than the liquefied

carbon dioxide Li is stored in the tank 11, the second

safety valve 31 is caused to function. The second safety valve 31 functions by transmitting the pressure inside the tank 11 to the second pilot valve 33 through the second pressure introduction line 42. When the pressure inside the tank 11 reaches the set pressure, the second pilot valve

33 is operated. When the second pilot valve 33 is operated,

the second safety valve 31 feeds the gas inside the tank 11

(vaporized gas of the liquefied gas L2) to the outside of

the tank 11. The gas fed from the second safety valve 31

is fed to the vent riser 9 through the connection pipe 45.

The gas is discharged to the outside from the vent riser 9.

In this way, the vaporized gas of the liquefied gas L2 is

discharged from the vent riser 9 disposed apart from the

second safety valve 31. In contrast, the vaporized gas of

the liquefied carbon dioxide Li is directly discharged from

the first safety valve 21. Therefore, even when the dry

ice is generated when the carbon dioxide gas is discharged

by the first safety valve 21, it is possible to prevent the

connection pipe 45 from being blocked due to the generated

dry ice.

The switching valve 43 selectively switches the

transmission destination of the pressure inside the tank 11

between the first pilot valve 23 and the second pilot valve

33. That is, the switching valve 43 may be switched as

follows. When the liquefied carbon dioxide Li is stored in

the tank 11, the pressure inside the tank 11 is transmitted to the first safety valve 21, and when the liquefied gas L2 is stored, the pressure inside the tank 11 is transmitted to the second safety valve 31. In this manner, the proper safety valves 21 and 31 can function depending on a storage object to be stored in the tank 11. Therefore, the discharge destination of the storage object in the tank 11 which is discharged from the safety valves 21 and 31 can be easily and safely switched.

[00591

(2) According to a second aspect of the floating

structures 1A and 1B, the floating structures 1A and 1B of

(1) further includes the detection unit 43s detecting the

transmission destination of the pressure inside the tank 11

in the switching valve 43, and the information output unit

43m outputting the information indicating the transmission

destination detected by the detection unit 43s to the

outside.

[00601

In this manner, the information indicating the

transmission destination of the pressure inside the tank 11

in the switching valve 43 which is detected by the detection

unit 43s is output to the outside by the information output

unit 43m. Therefore, an operator can easily recognize the

transmission destination of the pressure inside the tank 11

in the switching valve 43, based on the information output from the information output unit 43m.

[0061]

(3) According to a third aspect of the floating

structures 1A and 1B, in the floating structures 1A and 1B

of (1) or (2), the connection pipe 45 includes the

detachable pipe 49 forming a portion of the connection pipe

in an extending direction of the connection pipe 45, and

the connection pipe main body 48 forming a remaining portion

of the connection pipe 45. The detachable pipe 49 is

configured to be detached from the connection pipe main body

48.

[00621

In this manner, since the detachable pipe 49 serving

as a portion of the connection pipe 45 connected to the

second safety valve 31 is detached, the gas discharged from

the discharge port 34b of the second safety valve 31 is

immediately discharged to the atmosphere. Therefore, when

the first safety valve 21 is not normally operated in a

state where the liquefied carbon dioxide Ll is stored in

the tank 11, the connection pipe 45 is detached. In this

manner, even when the dry ice is generated by the gas of

carbon dioxide discharged from the discharge port 34b during

the operation of the second safety valve 31, it is possible

to prevent the connection pipe 45 from being blocked due to

the generated dry ice.

[00631

(4) According to a fourth aspect, there are provided

the floating structures 1A and 1B including the floating

main structure 2, the tank 11 disposed in the floating main

structure 2 to selectively store the liquefied carbon

dioxide Li and the liquefied gas L2 other than the liquefied

carbon dioxide Li, the safety valve 51 feeding the pressure

inside the tank 11 to the outside of the tank 11 when the

pressure inside the tank 11 reaches a predetermined set

pressure, the vent riser 9 disposed apart from the safety

valve 51 and discharging the gas to the outside, and the

connection pipe 55 connecting the safety valve 51 and the

vent riser 9 to guide the gas fed from the safety valve 51

to the vent riser 9. The connection pipe 55 includes the

detachable pipe 59 forming a portion of the connection pipe

in an extending direction of the connection pipe 55, and

the connection pipe main body 58 forming a remaining portion

of the connection pipe 55. The detachable pipe 59 is

configured to be detached from the connection pipe main body

58.

[00641

In this manner, when the liquefied carbon dioxide Li

is stored in the tank 11, since a portion of the connection

pipe 55 is detached, the gas discharged from the discharge

port 54b of the safety valve 51 can be immediately discharged to the atmosphere. Accordingly, even when the dry ice is generated by the gas of the carbon dioxide discharged from the discharge port 54b during the operation of the safety valve 51, it is possible to prevent the connection pipe 55 from being blocked due to the generated dry ice.

In addition, when the liquefied gas L2 is stored in

the tank 11, the vaporized gas of the liquefied gas L2 fed

from the safety valve 51 during the operation of the safety

valve 51 is discharged to the outside from the vent riser 9

through the connection pipe 55. In this way, while the

safety valve 51 is used for both the liquefied carbon

dioxide Li and the liquefied gas L2, the discharge form from

the safety valve 51 can be properly selected in accordance

with a type of the storage object to be stored in the tank

11. The operator can easily recognize that the detachable

pipe 59 is in a detached state. Therefore, the discharge

destination of the storage object in the tank 11 to be

discharged from the safety valve 51 can be easily and safely

switched. In addition, since the safety valve 51 can be

used for both the liquefied carbon dioxide Li and the

liquefied gas L2, costs for the facility can be reduced.

Industrial Applicability

[00651

According to the floating structure of the present disclosure, it is possible to easily and safely switch a discharge destination of a tank storage object discharged from the safety valve.

Reference Signs List

[00661

1A, 1B: Ship (floating structure)

2: Hull (floating main structure)

2a: Bow

2b: Stern

3A, 3B: Broadside

5: Upper deck

7: Superstructure

8: Cargo tank storage compartment

9: Vent riser

10: Tank facility

11: Tank

13: Loading pipe

14: Unloading pipe

20A, 20B: Safety valve system

21: First safety valve

22: Main valve

23: First pilot valve

24: Main valve valve casing

24a: Inflow port

24b: Discharge port

24d: Back pressure chamber

: Cylinder

s: Pressure introduction chamber

26: Valve body

27: Biasing member

28: Communication line

31: Second safety valve

32: Main valve

33: Second pilot valve

34: Main valve valve casing

34a: Inflow port

34b: Discharge port

34d: Back pressure chamber

: Cylinder

s: Pressure introduction chamber

36: Valve body

37: Biasing member

38: Communication line

41: First pressure introduction line

42: Second pressure introduction line

43: Switching valve

43m: Information output unit

43s: Detection unit

44: Pressure supply pipe

: Connection pipe

48: Connection pipe main body

49: Detachable pipe

51: Safety valve

53: Pilot valve

54b: Discharge port

: Connection pipe

58: Connection pipe main body

59: Detachable pipe

L: Stored gas

Li: Liquefied carbon dioxide

L2: Liquefied gas

Claims

Claims

[Claim 1]

A floating structure comprising:

a floating main structure;

a tank disposed in the floating main structure to

selectively store liquefied carbon dioxide and liquefied

gas other than liquefied carbon dioxide;

a first safety valve including a first pilot valve

operated when a pressure inside the tank reaches a

predetermined set pressure and discharging gas inside the

tank to an outside of the tank by operating the first pilot

valve;

a first pressure introduction line transmitting the

pressure inside the tank to the first pilot valve;

a second safety valve including a second pilot valve

operated when the pressure inside the tank reaches a

predetermined set pressure and feeding the gas inside the

tank to the outside of the tank by operating the second

pilot valve;

a vent riser disposed apart from the second safety

valve and discharging the gas to the outside;

a connection pipe connecting the second safety valve

and the vent riser to guide the gas fed from the second

safety valve to the vent riser; a second pressure introduction line transmitting the pressure inside the tank to the second pilot valve; and a switching valve selectively switching a transmission destination of the pressure inside the tank between the first pilot valve and the second pilot valve.
[Claim 2]

The floating structure according to Claim 1, further

comprising:

a detection unit detecting the transmission

destination of the pressure inside the tank in the switching

valve; and

an information output unit outputting information

indicating the transmission destination detected by the

detection unit to the outside.
[Claim 3]

The floating structure according to Claim 1 or 2,

wherein the connection pipe includes

a detachable pipe forming a portion of the

connection pipe in an extending direction of the connection

pipe, and

a connection pipe main body forming a remaining

portion of the connection pipe, and

the detachable pipe is configured to be detached from the connection pipe main body.
[Claim 41

A floating structure comprising:

a floating main structure;

a tank disposed in the floating main structure to

selectively store liquefied carbon dioxide and liquefied

gas other than liquefied carbon dioxide;

a safety valve feeding gas inside the tank to an

outside of the tank when a pressure inside the tank reaches

a predetermined set pressure;

a vent riser disposed apart from the safety valve and

discharging the gas to the outside; and

a connection pipe connecting the safety valve and the

vent riser to guide the gas fed from the safety valve to

the vent riser,

wherein the connection pipe includes

a detachable pipe forming a portion of the

connection pipe in an extending direction of the connection

pipe, and

a connection pipe main body forming a remaining

portion of the connection pipe, and

the detachable pipe is configured to be detached

from the connection pipe main body.