JPH039200A - Transport and storage method of low-temperature liquefied gas and its equipment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a new method for transporting and storing low-temperature liquefied gas and its equipment, and particularly relates to a method for transporting and storing low-temperature liquefied gas, and in particular to a method for transporting and storing low-temperature liquefied gas such as LNG, LPG, or L N x using a ship hull. The present invention relates to a method and equipment that can simplify the cargo handling work when transporting and storing cargo to a satellite base or the like, as well as simplifying the equipment for transporting and storing the cargo.

[Prior Art] In general, when transporting low-temperature liquefied gas such as LNG, LPG, or LN from a production area to a satellite base as a demand area, a waterway such as the sea is used between the production area and the demand area. In some cases, this is done on the hull of the ship.

A ship that transports such low-temperature liquefied gas has a tank containing the low-temperature liquefied gas. LNG.

Low temperature liquefied gas such as LPG or LN2 is -140
Since the i#l end low end flow temperature liquid is ~-160°C, the tank is molded from a low temperature material and covered with a cold insulator.

Additionally, in general, ships' tanks that transport this type of low-temperature liquefied gas have bulkheads that divide the inside of the tank into multiple parts to prevent the entire capacity of the stored low-temperature liquid from leaking out in the event that a part of the tank is destroyed due to some kind of accident. have. In this manner, the hull tank is provided with a bulkhead inside and is entirely made of low-temperature material. In recent years, in order to reduce transportation costs, ships for transporting this type of low-temperature liquefied gas have tended to become larger.

On the other hand, a low-temperature tank for accommodating and storing low-temperature liquefied gas transported by the above-mentioned ship is fixedly constructed at a satellite base serving as a demand site. Generally, this low-temperature tank is mainly composed of an inner tank that substantially contains the low-temperature liquid, and an outer tank that covers the inner tank and forms a cold insulating material layer. A large number of cryogenic tanks are arranged at the satellite base as necessary, and these tanks are provided with transport lines for receiving cryogenic liquid from the ship's hull. Like the tank, this transport line has piping made of low-temperature material, but both are covered with a cold insulating material. Furthermore, when the satellite base is surrounded by shallow sea, the above-mentioned transport line has to be extended out to sea a considerable distance from the base, resulting in an enormous amount of equipment.

[Problems to be Solved by the Invention] As mentioned above, ships for transporting low-temperature liquefied gas tend to be larger in size for the purpose of reducing transportation costs and transporting large quantities. There was a problem that the structure became complicated and expensive due to the provision of partition walls and the like inside.

In addition, as this type of ship becomes larger, the port facilities at the satellite base cannot keep up with it, and the transport line connecting the ship and the base's cryogenic tank becomes longer. remains, and the equipment and maintenance required to keep it cool, maintain it, and transport it continuously has become complicated. Furthermore, because the low-temperature tanks at the base are fixedly installed on the ground ring, there is a problem that when maintaining the inside of the tank, the tank cannot be used for its original function, especially because the base site is narrow. At times, there were problems in which effective use of space could not be achieved.

The present invention was created to solve the above problems,
The purpose is to provide a method for transporting and storing low-temperature liquefied gas that can simplify cargo handling operations and simplify the equipment as much as possible when transporting and storing low-temperature liquefied gas to satellite bases etc. using a ship's hull. It provides facilities.

[Means for Solving the Problems] To achieve the above object, the first invention provides a method for transporting and storing low-temperature liquefied gas such as LNG by ship to a satellite base, etc., in which the low-temperature liquefied gas is kept cold. A cryogenic tank unit is formed to be stored and floated underwater, a dock is formed at the satellite base for storing and installing the cryogenic tank unit, and the cryogenic tank unit is placed on the hull and transported. At the same time, the hull is lowered into the sea at the dock, and the cryogenic tank unit is floated on the sea and guided to the dock, where the water in the dock is drained and installed.

The second invention is an inner tank that is removably loaded on the loading deck of a ship and substantially stores the low-temperature liquefied gas, in a facility for transporting and storing low-temperature liquefied gas such as LNG by ship to a satellite base or the like. and a low-temperature tank unit having an outer tank forming a predetermined cold insulating layer on the outside of the inner tank, and an outer shell that surrounds the outer tank and provides buoyancy so that the entire tank floats in the water; A dock for storing the cryogenic tank unit; and a dock for transporting the cryogenic tank unit by placing it on a loading deck, sinking at least the deck into the water, floating the cryogenic tank unit in the water, and guiding it to the dock. It consists of a hull and a hull for carrying out operations.

[Function] With the above configuration, in the first invention, a low temperature tank unit is formed to keep the low temperature liquefied gas cool and contained and to float underwater, and this low temperature tank unit is stored and installed at the satellite base. The low-temperature tank unit is filled with low-temperature liquefied gas and stored at the refueling base, and the low-temperature tank unit is placed on the hull and transported to the dock. When the ship approaches the dock, the ship is lowered into the sea, and the cryogenic tank unit mounted on the ship is floated to the sea and guided into the dock. This simplifies the cargo handling work, and allows the cargo handling work to be carried out without bringing the ship close to the satellite base, making it easy to carry out cargo handling work even in shallow waterways.

Further, the low temperature tank unit can be installed by guiding the low temperature tank unit into the dock and then draining the inside of the dock.

Next, in the second invention, the low-temperature tank unit for transporting low-temperature liquefied gas is configured to be separated from the ship's hull, so that the transfer from the ship's hull to the satellite base can be achieved by floating it on the sea. By separating the tank unit from the ship's hull and storing it in the dock of the satellite base, it will function as a storage tank for the base.

[Example] An example of the equipment according to the present invention will be described with reference to FIGS. 2 to 4.

The low-temperature tank unit 1 includes an inner tank 2 that substantially contains low-temperature liquefied gas, an outer tank 4 for forming a predetermined cold insulation material layer 3 on the outside of the inner tank 2, and a structure surrounding the outer tank 4. It mainly consists of an outer shell 5 that provides buoyancy to float in the water. The inner tank 2 is made of a low-temperature material such as a stainless steel plate to store a low-temperature liquefied gas such as LNG or LPG.

An outer tank 4 surrounding the inner tank 2 is used to form a cold insulating material layer on the outer periphery of the inner tank 2, and is made of a room-temperature material such as a steel plate. In addition, the cold insulating material layer 3 is generally formed by using pearlite grains, which are filled between the inner tank 2 and the outer tank 4.

Next, the outer shell 5 is used to give sufficient buoyancy to the inner tank 2 and the outer tank 4 in water when the low-temperature liquefied gas is stored in the inner tank 2. It reinforces the outer tank 4 including the outer tank 4, and is formed from a steel plate or the like. In addition, the outer shell 5 is shown in Figures 2 to 4.
As shown in the figure, it is formed into a cylindrical shape with a bottom, and an outer tank 4 including the inner tank 2 is housed in an outer shell 5. The inner diameter of the outer shell 5 is set larger than the outer diameter of the outer tank 4, and the space between the outer shell 5 and the outer shell 5 is filled with pearlite grains as a cold insulating material or is made hollow so as to sufficiently exert the above-mentioned buoyancy. It is composed of As shown in FIG. 4, a lid plate 7 is integrally formed at the upper opening of the outer shell 5 to close it.

Note that the liquefied gas contained in the inner tank 2 is, for example, LN.
Since the specific gravity of G is 0.46 (+/cn'), if the outer shell 5 is hollow and has sufficient reinforcing properties, the low temperature tank unit 1 will float in the water.

Furthermore, a nozzle 6 for taking out the low-temperature liquefied gas contained in the inner tank 2 is provided at the top of the low-temperature tank unit 1 .

Next, the hull for transporting the low-temperature tank unit 1 has a flat loading deck 9 and a ballast tank or the like having a function of submerging the loading deck 9 at least in the sea. Further, the hull 8 is provided with a living area 10, and within this living area 10, a wheelhouse, etc. is provided for navigating the hull 8 or for lowering the hull 8 into the sea, as described above. There is.

Further, as shown in FIG. 2, the mounting deck 9 is configured so that a plurality of low temperature tank units 1 are mounted thereon. Further, as shown in FIG. 5, the loading deck 9 is provided with an engaging pin 11 for fixing the low temperature tank unit 1 placed thereon. On the other hand, the low temperature tank unit 1 is provided with a hook member 12 that engages with the engagement pin 11.

A drive device 14 provided on the upper part of the low temperature tank unit 1 is connected to this hook member 12 via an operating rod 13, and this drive device 14 automatically moves the hook member 12
is configured to engage and disengage from the engagement pin 11.

On the other hand, as shown in FIG. 6, the low temperature tank unit 1 is provided with a connecting device 15 for connecting the units 1 that are stacked adjacent to each other on the deck 9. This connecting device 15 is mainly composed of a hook member 16 provided on one low temperature tank unit 1 and an engagement pin 17 provided on the other unit 1. The hook members 16 are provided at predetermined intervals on an operating rod 18 provided along the height direction of the tank unit 1. This operating lever 18
A drive device 19 is provided on the upper part of the drive unit 19, and the hook member 16 swings when the operating rod 18 is rotated, thereby causing the engagement pin 17 to swing.
It is configured to be connected to and disconnected from the

The hook member 16 and the engagement pin 17 are housed in a recess formed in the outer shell 5 of the low-temperature tank unit 1, and when the hook member 16 is removed from the retaining pin 17, the hook member 16 and the engagement pin 17 are accommodated in the recess. is housed so that the hook member 16 does not protrude from the outer shell 5.

Next, a dock 20 for storing and installing the cryogenic tank unit 1 is provided facing the sea of the satellite base to receive the cryogenic tank unit 1 floating on the sea. This dock 20 includes a storage chamber 21 consisting of a recess formed on the bay side of the satellite base;
It mainly consists of a gate 22 which is vertically movable and is provided on the sea side of the river. The storage chamber 21 has an inner diameter larger than the outer diameter of the low-temperature tank unit 1, and is configured to be filled with seawater so that the low-temperature tank unit 1 can be received while floating on the sea.

On the other hand, Gate 22 is the control room of the satellite base (
It is configured so that it can be moved up and down by remote control from a device (not shown) to open and close the storage chamber 21 on the sea side. By lowering the gate 22 and closing the sea side of the storage room 21, the dock 20 is configured to completely block the flow of seawater between the interior of the dock 20 and the sea.

The dock 20 also includes a drainage device (not shown) for draining the interior of the storage chamber 21 with the gate 22 closed.

Further, the hull 8 is provided with means for guiding the cryogenic tank unit 1, which is separated from the hull 8 and floats on the sea, to the dock 20.

Next, a method for transporting and storing low-temperature liquefied gas using the above-mentioned equipment will be explained with reference to FIGS. 1(a) to (f).

Low-temperature liquefied gas is filled into low-temperature tank units 1 at a refueling base in its production area, etc., and as shown in FIG. Transported to base. While the hull 8 is sailing on the sea, each cryogenic tank unit 1 is fixed to the ship #8 by engaging the hook member 12 provided at its lower part with the engagement pin 11 provided on the loading deck 8. 9
The units 1 stacked adjacent to each other are connected by the connecting device 15 described above.

When the hull 8 approaches the dock 20 of the satellite base, the hull 8 is stopped and the depth of water is reached at which buoyancy occurs on the low-temperature tank unit 1 mounted and fixed on the loading deck 9, as shown in Fig. 1(b). Seawater or the like is introduced into the ballast tank of the hull 8, and the hull 8 is lowered into the sea.

Next, the hook member 16 is removed from the engagement pin 17 of the connecting device 15 that connects the low temperature tank units 1 to each other to release the connection between the units 1. Next, the hook members 12 provided at the bottom of the cryogenic tank unit 1 located at the rear of the hull 8 are disengaged from the engagement pins 11 provided on the loading deck 9, as shown in FIG. 1(C). The units 1 are separated from the hull 8 one by one and floated onto the sea.

On the other hand, in the dock 20 that houses the low-temperature tank unit 1 containing the new low-temperature liquefied gas, the gate 22 is opened and the storage chamber 21 is filled with seawater in advance, as shown in FIG. 1(d).

Next, the low-temperature tank unit 1 floating on the sea is guided into the dock 20 by a tugboat or the like (not shown), and then the gate 22 is lowered as shown in FIG. Cut off distribution.

Next, a drainage device (not shown) provided in the dock 20 is driven to drain the seawater in the dock 20 housing the low temperature tank unit 1. Low temperature tank unit 1 is dock 20
As the water level inside the dock 20 decreases, it descends and sits on the bottom surface of the dock 20. As a result, the low temperature tank unit 1 is installed in the dock 20, and the transportation of low temperature liquefied gas to the satellite base is completed.

At the satellite base, low-temperature liquefied gas is stored in a low-temperature tank unit 1 installed in the dock 20, taken out from the nozzle 6 installed at the top of the unit 1, and supplied to consumers such as general households. be done.

On the other hand, the cryogenic tank unit 1, which has become empty after the entire capacity of the stored low-temperature liquefied gas has been supplied to the consumer, is removed from the dock 20 and transported again to a refueling base such as a production area. In this case, the empty cryotank unit 1 is stored in the above-mentioned 1. The low-temperature liquefied gas is transported to the refueling base using the reverse procedure.

That is, first, with the empty low temperature tank unit 1 installed in the dock 1, seawater is allowed to flow into the dock 20. The low temperature tank unit 1 is given buoyancy by the seawater flowing into the dock 20 and floats inside the dock 20.

Next, after the level of seawater flowing into the dock 20 becomes equal to the level of seawater on the sea side, the gate 20 is fully opened and the low temperature tank unit 1 is guided to the sea by a tugboat or the like (not shown).

On the sea of the satellite base, the hull 8 is kept waiting by sinking its loading deck 9 into the sea in order to collect the empty cryogenic tank unit 1. The hull 8 fixes an empty cryogenic tank unit 1 on its loading deck 9, connects the units 1 placed adjacent to each other, and then floats to carry the empty cryogenic tank unit to a refueling base such as a production area. Transport 1.

Next, the operation and effects of this embodiment will be explained.

By lowering the hull 8 into the sea at the satellite base and guiding the cryogenic tank unit 1 mounted on the hull 8 into the dock 20, low-temperature liquefied gas can be transferred from the hull 8 to the satellite base, simplifying cargo handling operations. It is possible to carry out cargo handling operations without bringing the hull 8 close to the satellite base, and cargo handling operations can be carried out easily even in shallow waterways. In addition, the cryogenic tank unit 1 is connected to the hull 8.
By being separated from the base, stored and installed in the dock 20 of the satellite base, it functions as a storage tank for the base.

Since the low-temperature tank unit 1 for transporting low-temperature liquefied gas is configured separately from the hull 8, the manufacturing cost of the hull 8 for transporting low-temperature liquefied gas can be reduced,
In addition, by transferring the low-temperature liquefied gas from the hull 8 to the satellite base along with the low-temperature tank unit 1, the low-temperature liquefied gas remaining in the transport line connecting the hull 8 and the satellite base and the transport line is kept cool and maintained for continued transport. This eliminates the need for equipment and maintenance, which has the effect of significantly reducing construction and maintenance costs for satellite bases.

Furthermore, since the low-temperature tank unit 1 is simply housed and installed in the dock 20, when maintaining the inside thereof, it is removed from the dock 20 and carried out at a predetermined factory, and the dock 20 is always available for use. unit 1
This has the effect of making effective use of the space at the satellite base.

Furthermore, since the low-temperature tank unit 1 itself can be manufactured in a predetermined factory, a constant quality can be ensured and a product with high safety can be obtained.

[Effects of the Invention] In summary, according to the present invention, the following excellent effects are achieved.

(1) When transporting and storing low-temperature liquefied gas to a satellite base, etc. using a ship's hull, the cargo handling work can be simplified.

(2) Facilities can be simplified because low-temperature liquefied gas is transported to and stored at satellite bases using the ship's hull.

(3) The cost of transporting and storing low-temperature liquefied gas can be significantly reduced, as well as the equipment cost.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the method according to the present invention, FIG. 2 is a partially fragmented side view showing an embodiment of the equipment according to the present invention, and FIG. 3 is a plan view of FIG. FIG. 4 is a partially exploded perspective view showing one embodiment of the equipment according to the present invention, and FIG. 5 is a longitudinal cross-sectional view showing a mechanism for fixing the low temperature tank unit to the hull.
FIG. 6 is a longitudinal sectional view showing a mechanism for interconnecting low temperature tank units. In the figure, 1 is a low temperature tank unit, 2 is an inner tank, 3 is a cold insulation layer, 4 is an outer tank, 5 is an outer shell, 8 is a hull, 9 is a loading deck, 2
0 is the dock.

Claims (1)

[Claims] 1. In a method of transporting and storing low-temperature liquefied gas such as LNG by ship to a satellite base etc., a low-temperature tank unit is formed to keep the low-temperature liquefied gas cool and stored and float it underwater. At the same time, a dock will be formed at the satellite base to house and install the cryogenic tank unit,
The cryogenic tank unit is placed on the ship's hull and transported, the ship's body is lowered into the sea near the dock, the cryogenic tank unit is floated on the sea, and then guided to the dock to drain the water in the dock. A method for transporting and storing low-temperature liquefied gas, characterized in that it is installed. 2. It is removably loaded on the loading deck of the ship, and includes an inner tank that contains low-temperature liquefied gas, an outer tank that forms a predetermined layer of cold insulation material on the outside of the inner tank, and a tank that surrounds the outer tank and is completely underwater. a cryogenic tank unit having an outer shell that provides buoyancy to make it float; a dock formed at the satellite base for accommodating the cryogenic tank unit; and a dock for placing the cryogenic tank unit on a loading deck and transporting it. A low-temperature liquefied gas transportation and storage facility, comprising: a hull for lowering at least the deck into the water, floating the low-temperature tank unit in the water, and guiding the low-temperature tank unit to the dock.