WO2003006308A1

WO2003006308A1 - Gas hydrate carrier

Info

Publication number: WO2003006308A1
Application number: PCT/JP2002/006901
Authority: WO
Inventors: Tatsuya Takaoki; Kazushi Hirai; Tadashi Ishiyama; Susumu Tanaka
Original assignee: Mitsui Engineering & Shipbuilding Co.,Ltd.
Priority date: 2001-07-09
Filing date: 2002-07-08
Publication date: 2003-01-23
Also published as: JPWO2003006308A1; KR100913747B1; JP4044899B2; KR20040015732A

Abstract

A carrier for transporting gas hydrate, wherein one or more holds are provided in a hull in longitudinal and lateral directions and a loading equipment for distributing powder or granular gas hydrate into the holds is installed in the hull, an unloading equipment for unloading the powder or granular gas hydrate stored in the holds to the outside of the carrier is installed in the hull, and the upper side of the holds and a gas hydrate access area is sealingly covered with an outer shell.

Description

Specification

Gas hydrate transport ship

Technical field

The present invention relates to a gas hydrate transport ship for transporting a so-called gas hydrate composed of gas mainly composed of methane such as natural gas and water.

Background technology

Conventionally, natural gas has been transported as liquefied natural gas (hereinafter LNG) or as high-pressure gas filled in cylinders.

However, LNG needs to be transported at a cargo temperature of 162 ° C, so special transport vessels with specially manufactured expensive storage tanks, that is, LNG vessels, are required. . LNG also needs to invest a lot of energy in its production to turn natural gas into a liquid at -162 ° C. Also, LNG is very dangerous because if the temperature control is malfunctioning, it evaporates rapidly. In addition, LNG is not suitable for long-term storage because of its extremely low temperature, as described above, the vaporization rate is high.

On the other hand, methane-based gas such as natural gas is attracting attention as a raw material for clean energy sources and various products, and methane such as natural gas is mainly used for transportation and storage. Gas to be artificially or industrially Research into gas hydrate (NGH) is being conducted.

NGH has a crystal structure in which gas molecules are contained one by one in a basket made of water molecules. For example, in methane hydrate, 1 m ³ of methane hydrate at normal pressure is used. It is said to be occluded to methane of 1 6 4 m ³ in. Of these, the volume of water is 0. 8 m ^3.

Thus, because of its high gas storage capacity, methane hydrate is attracting attention as a new natural gas transport and storage alternative to LNG. The methane gas density in methane hydrate is about 3.5 times lower than that of LNG. However, when manufactured artificially or industrially, the liquefaction temperature, that is, the liquefaction temperature like LNG, It is said that there is no need to cool to below 162 ° C, which significantly improves energy efficiency.

When producing methane hydrate artificially, for example, spray water or antifreeze from the spraying means into a pressure vessel maintained at a temperature of 1 to 100 ° C and a pressure of 30 to 100 atm. At the same time, methane gas is supplied from the supply pipe. Alternatively, inject methane gas into water or antifreeze. Then, water or antifreeze and methane gas are synthesized to form powdery methane hydrate.

The powdered methane hydrate has a filling rate of Because the volume of hydrate / the volume of the storage container) is small, powder methane hydrate may be formed into pellets by a granulator such as a pelletizer during transportation or storage. I have. The transport of such gas hydrates requires new transport vessels to replace LNG carriers.

Disclosure of the invention

The present invention has been made from such a demand.

However, the purpose is to provide a gas hydrate transport vessel suitable for transporting gas hydrate.

A gas hydrate transport ship of the present invention capable of achieving the above object is a transport ship for transporting gas hydrate, and has a hull provided with at least one hold in each of a bow direction and a lateral direction. In addition, a loading device for distributing powder or granular gas hydrate to each hold shall be provided, and an unloading device for discharging powder or granular gas hydrate stored in said hold to the outside of the ship shall be provided, Further, the invention is characterized in that the upper part of the hold and the gas hydrate carry-in / out area are covered and sealed with an outer shell.

In this way, the hull is provided with one or more holds each in the bow and stern directions and in the lateral direction thereof, and is provided with a loading device for distributing powder or granular gas hydrate to each hold, and in the hold. Flour or grain stored An unloading device that discharges the gas hydrate out of the ship is installed, and the upper part of the hold and the gas hydrate carry-in / out area are covered with an outer shell and sealed, so that the powder or granular gas hydrate can be removed. Safe and efficient cargo handling and safe transport have become possible. In addition, gas hydrate has a crystal structure in which gas molecules are contained one by one in a basket made of water molecules, so that even if temperature control or the like becomes abnormal, gas hydrate can evaporate rapidly. And is extremely safe compared to LNG. In addition, gas hydrate has a lower vaporization rate than LNG, and is suitable for long-distance transportation and long-term storage.

In particular, by pelletizing a powdery gas hydrate with a granulator, the fluidity and filling efficiency of the hydrate are improved, and cargo handling and transportation become easier.

Conveyor type and shoot type can be cited as loading equipment.

The conveyor-type loading device includes a first transfer means for transferring the powder or granular gas hydrate in the bow direction, and a distribution means for distributing the powder or granular gas hydrate from the first transfer means to each hold. It comprises supply means for supplying a powder or granular gas hydrate from the outboard to the first transfer means, and cylindrical sealing means for covering the outside of the supply means. Therefore, powder or granular gas hydrate can be smoothly and efficiently loaded into the hold.

On the other hand, the chute-type loading device has a cylindrical moving part movable toward the bow direction of the hull, a plurality of distribution shots provided in the moving part, and a moving part between the moving part and the hull. It is composed of the provided seal part.

Therefore, powder or granular gas hydrate can be smoothly and efficiently loaded into the hold than a conveyor-type loading device.

Below the distributing means, it is desirable to provide an impact mitigation means for alleviating the impact when the powder or granular gas hydrate falls, or to install a blending plate having randomly provided large and small holes.

The unloading device includes a second transfer means disposed below the hold, and a transfer means for transferring the powder or granular gas hydrate transferred by the second transfer means to a cargo handling device outside the ship. Have been.

Therefore, the powder or granular gas hydrate in the hold can be unloaded smoothly and efficiently. As the second transfer means, a sliding plate having a myriad of gas ejection holes and a gas hydrate transport box arranged on the sliding plate, or a cylindrical object, and a gas hydrate transfer box installed in the cylindrical object What consists of a perforated plate and a gas body that floats the gas hydrate on the perforated plate Can be.

In addition, when conveying powder or granular gas hydrate, airflow conveyance can be applied entirely or partially. Brief description of the drawings FIG. 1 is a perspective view of a gas hydrate transport ship according to the present invention. is there.

FIG. 2 is an enlarged perspective view of a main part of the gas hydrate transport ship according to the present invention.

FIG. 3 is a cross-sectional view of the gas hydrate transport ship according to the present invention.

Fig. 4 is a vertical sectional view of the loading / unloading area.

FIG. 5 is a longitudinal sectional view of the lift device.

FIG. 6 is a front view of the dispensing device.

FIG. 7 is a perspective view of a chute.

FIG. 8 is a perspective view of the dispensing device.

FIG. 9 is an expanded view of the conveyor.

FIG. 10 is a diagram showing a holding state of the conveyor.

FIG. 11 is a side view showing another embodiment of the lift device.

FIG. 12 is a longitudinal sectional view of the dispensing device.

FIG. 13 is a perspective view of the dispensing device.

FIG. 14 is a perspective view showing another embodiment of the transfer device. FIG. 15 is an explanatory view of crush prevention means.

FIG. 16 is a perspective view of the blending device.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this embodiment, an example is described in which a gas hydrate obtained by molding a powdery gas hydrate into a pellet by a granulator such as a pelletizer is transported.

As shown in FIG. 1, the gas hydrate transport ship 1 has a large number of holds 3 in a hull 2. These holds 3 are arranged in a grid pattern to prevent the gas halide stored in the hold 3 from collapsing. As shown in FIG. 3, the hold 3 has an input port 4 at its upper end and a discharge port 5 at its lower end. The diameter D of the outlet 5 is desirably set to at least about four times the apparent diameter of the pellet-like gas hydrate a. In addition, it is desirable to set the angle of inclination の at the bottom of the hold to 20 to 50 °.

Immediately below the above-mentioned inlet 4, a vertically movable baffle and hatch 6 is provided to uniformly load the pellet-shaped gas hydrate a and the pellet-shaped gas hydrate a falls to the bottom of the hold 3 Care is taken not to break when it is done.

In this example, hold 3 is arranged in three columns The exposed part is covered with a heat insulating material 7 such as urethane foam, plywood, balsa, perlite, etc., and the interior of the cargo hold 3 is maintained at a predetermined temperature, for example, 15 ° C to 130 ° C. It is about to hold.

In addition, a medium with low thermal conductivity such as water or oil or antifreeze liquid is sealed in a jacket (not shown) provided outside the hold 3, and the inside of the hold 3 is maintained at a predetermined set temperature. There is no problem. Further, it is possible to circulate the refrigerant in a cooling jacket (not shown) provided outside the hold 3 and forcibly cool the inside of the hold 3 to a predetermined set temperature. In the figure, 8 indicates a gate and 9 indicates a ballast tank.

As shown in Fig. 4, the carry-in / out area 10 is behind the hold 3. Referring back to FIG. 1, the transport ship 1 includes a conveyor-type loading device 11. The loading device 11 includes a first conveyor 12, a distribution device 13, and a supply device 14.

As described above, the hold 3 is in a three-row column, but the first conveyor 12 is provided directly above each hold group 30. In addition, the distribution device 13 includes a distribution plate 15 that can move intermittently in the bow direction along the first conveyor 12. The distribution plate 15 is provided obliquely with respect to the first conveyor 12, and has a pellet-shaped gas hydrate transported by the first conveyor 12. G is supplied or distributed to the designated hold 3.

A supply device 14 is provided in the carry-in / out area 10 where the rear end of the first conveyor 12 is located. The supply device 14 includes a main conveyor 16 and a slide conveyor 17 capable of sliding (see FIG. 2). As the slide conveyor 17 moves back and forth, that is, in the lateral direction of the hull 2, the pellet-shaped gas hydrate a is distributed to the first conveyor 12 respectively. ing.

However, when the main conveyor 16 is operated after the tip of the slide conveyor 17 is positioned on the predetermined first conveyor 12, the pellet gas hydrate a becomes the main conveyor 1. From 6 is supplied to the first conveyor 12 via the slide conveyor 17. The gas hydrate a in the form of a bullet supplied to the first conveyor 12 is transferred in the bow direction by the first conveyor 12. Then, the hand going to the distribution plate 15 set just above the predetermined hold 3 is blocked, and the drop is stored in the predetermined hold 3 and stored.

As shown in FIG. 1, an outer shell 19 is provided on the deck 18 so as to cover the hold group 30 and the carry-in / out area 10 so as to seal the space therebetween. As shown in Fig. 2, the side of this outer shell 19 is located in the loading / unloading area. An opening 20 is provided. A sealing means 21 for sealing the supply device 14 is detachably attached to the opening 20. The sealing means 21 has a bellows-like shape at the tip portion 22 so that it can freely expand and contract. The opening 20 has a hatch (not shown).

As shown in FIG. 4, the gas hydrate transport ship 1 includes a conveyor-type unloading device 23. The unloading device 23 uses a second conveyor 24 provided below the hold group 30 and a pellet-shaped gas hydrate a transferred by the second conveyor 24 to the outboard cargo handling device 25 ( (See Fig. 5).

As shown in FIG. 5, the vertical lift device 26 is composed of a tank 27 with a shunt and a screw conveyor 28 erected on the tank 27. A funnel-shaped chute 29 is provided between the two conveyors 24 and the tank 27.

The conveyor 31 is used as the outboard cargo handling device 25. The conveyor 31 is inserted through the opening 20 provided on the side surface of the outer shell 19 described above. The conveyor 31 is not limited to a screw conveyor, and a belt-shaped conveyor can be used. 21 indicates a bellows-like sealing means. Thus, the pellet-shaped gas hydrate a discharged into the tank 27 by the second conveyor 24 is transported upward by the vertical screw conveyor 28, and is transferred to the screw conveyor 28. It is supplied from the duct 32 to the conveyor 31 of the cargo handling device 25. And it is unloaded outside the ship by Competition 31.

The vertical screw conveyor 28 that lifts the gas gas a in the form of a pellet and the conveyor 31 for loading and unloading use gas such as carbon dioxide gas, nitrogen gas, and methane gas as the pressurized gas. It is desirable. Also, it is desirable to sail while spraying water on the deck 18 and the outer shell 19 during navigation.

In the above description, the belt conveyor type loading device has been described. However, the following chute type loading device can be applied. Devices having the same function are given the same reference numerals, and detailed description is omitted.

As shown in Fig. 6, the loading type loading device 11a is equipped with a bogie 34 on a bow-to-sail rail 33 mounted on a deck 18 and distributed to the bogie 34. A device 35 is provided. As shown in FIG. 8, the distributing device 35 is made up of a hopper 36 and a plurality (three in the figure) of chutes 37 a, 27 b, and 37 c attached to the hopper 36. It is configured.

These shoots 37a, 27b, and 37c are the sixth As shown in the figure, it is provided so as to simultaneously correspond to three holds 3 arranged in a row. Further, as shown in FIG. 7, the distributing device 35 has a seal plate 38 having a multi-section structure such as a shirt. The seal plate 38 is provided endlessly, and its ends are air-tightly attached to the front and rear ends of the hopper 36, respectively. The gap between the sealing plate 38 and the outer shell 19 installed on the deck 18 is also sealed by a sealing material (not shown). Further, as shown in FIG. 8, the hopper 36 is partitioned into chute 37 a, 27 b and 37 c by partition plates 39 a and 39 b.

Then, when the pellet-like gas hydrate a is supplied from the duct 40 connected to the hopper 36, it is arranged in the lateral direction through the chutes 37a, 27b and 37c. Pellet gas hydrate a is simultaneously supplied to the three holds 3.

A pipe conveyor can be used as the above-mentioned cargo handling conveyor. Various types of pipe conveyors are known. For example, as shown in FIGS. 9 and 10, a plurality of semicircular fins 41 are formed at a predetermined pitch by a conveyor 42. When attached to the gas, the pellet-shaped gas hydrate a can be transported more reliably.

In addition, as a lift device, a vertical screw Instead of the bear 28, for example, a lift device 26a as shown in FIG. 11 can be used. This lift device 26a is a device in which a large number of buckets 46 are attached to an endless member 45 that extends over a pair of upper and lower wheels 43, 44. The bucket interval is large on the side where a is to be lifted (left side in the figure), and small on the return side (right side in the figure).

In addition, a cylinder system (not shown) can be used as the lift device. This device has a structure in which a piston-like object in a vertical cylinder is raised and lowered by a hydraulic cylinder.

As the dispensing device, a floating dispensing device 47 shown in FIGS. 12 and 13 can be used. The dispensing device 47 ejects gas b from a large number of small holes 49 provided in a passage 48 and transfers the gas b into a box 50 containing a pellet-shaped gas hydrate a. .

Further, as shown in Fig. 14, a knitted fabric 52 is installed in the pipe 51, and a gas such as methane gas is blown out from the knit of the fabric 52 to form a pellet-like gas hydrate a. Liquidity can be increased.

Hold 3 is an ultrasonic transducer attached to the bottom By vibrating (not shown) or rotating a stirring blade (not shown) provided in the hold, it becomes easy to remove the pellet-shaped gas hydrate a.

In addition, a rubber coating (not shown) is attached to the bottom of the hold 3, and when the pellet-shaped gas hydrate a is dispensed, gas is injected between the hold 3 and the coating to form a hopper. It is also conceivable to deform it.

Also, as shown in Fig. 15, when a movable shutter 53 with a ladder is provided below the conveyor 12 and rotated as shown by the arrow, the impact of the pellet-shaped gas hydrate a falls. Can be relaxed. Other examples of the shock mitigation method include a method using a slide sheet, a method using a curved tube, and a method using a chin-shape distributor.

In order to improve the filling rate of the gas-hard plate a in the form of a pellet, for example, as shown in FIG. 16, a large-diameter hole 56 is provided below the distribution means (duct) 54. And a mixing plate 55 with small holes 57 randomly arranged, filling the gap between the large-diameter pellet gas hydrate a and the small-diameter pellet gas hydrate a " It can be done.

As another cargo handling method, for example, an air flow transfer method can be cited. For example, the mixing ratio is set to 10 to 15 and, for example, a pellet-like The gas hydrate. A is transported entirely by air flow, or is transported using methane gas only in vertical transport, and is transported outboard using a no-conveyor. Main gas is supplied and circulated from land.

In addition, a method in which a pellet-like gas hydrate is conveyed by a pumping gas (120 ° C) and simultaneously cooled (120 ° C) can be adopted.

Industrial applicability

In the above description, the case of transporting a pellet-shaped gas height and a rate has been described. However, the present invention can be applied to the case of transporting a powdery force and a hydrate.

Claims

5 Scope of request

1. A transport ship that transports gas hydrates. The hull is provided with one or more holds in the hull and transverse directions, and powder or granular gas hydrate is distributed to each hold. A loading / unloading device for discharging powder or granular gas hydrate stored in the hold to the outside of the ship is provided.Furthermore, the upper part of the hold and the gas hydrate carry-in / out area are covered with a shell. A gas hydrate transport ship characterized by being covered and sealed.

2. A first transferring means for transferring the powder or granular gas hydrate in the bow direction, and a distributing means for distributing the powder or granular gas hydrate to each hold from the first transferring means. 2. The gas hydrate transport ship according to claim 1, comprising supply means for supplying powder or granular gas hydrate to the first transfer means from outside the ship, and cylindrical sealing means for covering the outside of the supply means.

3. A cylindrical moving part capable of moving the loading device toward the stern of the hull, a plurality of distribution chutes provided on the moving part, and a seat provided between the moving part and the hull. 2. The gas hydrate transport ship according to claim 1, wherein the gas hydrate transport ship comprises:

4. Provide an impact mitigation means below the distribution means to reduce the impact of powder or granular gas hydrate when it falls. The gas hydrate transport ship according to claim 2 or 3, wherein

5. The gas hydrate transport ship according to claim 2 or 3, wherein a blending plate having randomly large and small holes is provided below the distribution means.

6. The unloading device is composed of a second transfer means arranged below the hold, and a transfer means for transferring the powder or granular gas hydrate transferred by the second transfer means to a cargo handling device outside the ship. The gas hydrate transport ship according to claim 1, wherein the ship is configured.

7. The gas hydrate transport ship according to claim 6, wherein the second transfer means comprises a slide plate having countless gas ejection holes, and a gas hydrate transport box disposed on the slide plate.

8. The gas passage according to claim 6, wherein the second transfer means comprises a cylindrical object, a perforated plate provided in the cylindrical object, and a gas body for floating a gas hydrate on the perforated plate. Drain transport ship.

9. The gas hydrate transport ship according to claim 6, wherein airflow transportation is applied entirely or partially when the powder or granular gas hydrate is transported.