KR20170031651A - Liquefied-gas transport vessel and liquefied-gas transport vessel designing method - Google Patents

Abstract

[PROBLEMS] To provide a liquefied gas transportation line capable of efficiently transporting liquefied gas in the region and within a short distance as well as LNG, multi-gas such as LPG, ethane, and ethylene, And a method of designing a liquefied gas transport line.
[MEANS FOR SOLVING PROBLEMS] A structure of a low-temperature liquefied gas tank having a total capacity of 60,000 m 3 to 90,000 m 3, a low-temperature liquefied gas tank having a heat-radiating structure for LNG, a structural strength of a low-temperature liquefied gas tank, When the structural strength is assumed to be the structural strength for mounting LNG or ethane or ethylene or LPG and the structure of the hull structure is installed in a low temperature liquefied gas tank, when LNG is mounted alone, when ethane, ethylene or LPG is mounted alone, or when LNG , Ethane, Ethylene, and LPG mixed in the case of a combination of the three cases, enough to navigate in the navigation to have sufficient restoration performance for freeboard and slope.
[Selectivity] Fig. 1

Description

[0001] LIQUEFIED-GAS TRANSPORT VESSEL AND LIQUEFIED-GAS TRANSPORT VESSEL DESIGNING METHOD [0002]

The present invention relates to a method of designing a medium gas volume multi-gas liquefied gas transporting line and a liquefied gas transporting line from 60,000 cubic meters to 90,000 cubic meters, which is suitable for short-distance transportation and secondary transport in the region.

LNG carriers that transport LNG (liquefied natural gas) are becoming larger and larger, and it is believed that such large LNG carriers will increase in the future. In transporting the LNG, the main component of the LNG is methane (CH4), the pressure at the time of transporting the LNG in the liquid state is atmospheric pressure, the temperature is minus 162 deg. C and the liquid ratio of methane as the main component is 0.43. Depending on the composition ratio, the liquid ratio is 0.43 to 0.48. Therefore, in order to keep the tank at a low temperature, a heat dissipation structure such as a heat insulating layer is provided. In addition, since the specific gravity of the liquefied natural gas is as low as 0.5 or less, the volume of the tank is larger than that of the hull.

In recent years, with regard to ship transportation of this LNG, it is becoming necessary to carry out short-distance transportation by ship and secondary transport within the region. Especially, in Japan, LNG import / There are a lot of 10,000 cubic meters to 90,000 cubic meters. In response to this, there are actually 60,000 cubic meters to 90,000 cubic meters of medium-sized LNG carriers. It was done.

However, this membrane-type tank is vulnerable to sloshing and is not allowed to operate in a semi-mounted state in which occurrence of sloshing is likely to occur. Since the tank is a two-room home, It is suitable for medium-sized liquefied gas transport vessels of 60,000 cubic meters to 90,000 cubic meters, which are used for short-distance transportation such as secondary transport in the region, since it is not possible to load and dispense the necessary small volume for voyage while distributing LNG to multiple ports. There is a problem that it is not.

As a countermeasure for this sloshing, for example, as described in Japanese Patent Application Laid-Open No. 6-123569, the adoption of a MOSS type low-temperature liquefied gas tank is considered and the transportation scale is not described. However, An LNG having three to five gas tanks is disclosed.

On the other hand, medium-scale liquefied gas transportation may be carried out only for LNG. In recent years, however, not only LNG but also ethane (C 2 H 6) and ethylene (C 2 H 4) Therefore, in addition to the transportation of LNG and LPG, it is also required that the transportation of ethane and ethylene is also possible in terms of efficient utilization of the liquefied gas transportation line.

However, as for LPG (liquefied petroleum gas), the same medium-scale LPG ship has been proven. In addition, there is an annual sales of 3,500 tons of ethylene loaded with ethylene as ethylene. However, depending on the situation, LNG, LPG, Medium-scale liquefied gas carriers of 60,000 cubic meters to 90,000 cubic meters capable of loading and transporting multi-gas in the same liquefied gas carrier have not yet been manufactured.

This LPG is a gas combustion mainly composed of propane and butane, and is liquefied at a relatively high temperature even under atmospheric pressure. The LPG is heavier than LNG and has a larger amount of heat per unit volume than LNG. For example, at atmospheric pressure (about 1.0 atm), butane is liquefied at minus 0.5 ° C to minus 11.7 ° C and propane at minus 42.1 ° C.

Furthermore, ethane is a component which is included next to methane in natural gas and is also obtained as a by-product in petroleum gas when oil is produced. The boiling point of ethane is minus 89 ° C at normal pressure and the specific gravity of liquid is 0.55. The boiling point of ethylene is minus 104 ° C at normal pressure and the specific gravity at transport is 0.57. The temperature and pressure at the time of transporting the ethylene in the liquid state are minus 104 캜 and 0.1 MPa (about 1.0 atm).

If this ethylene is to be mounted on the LNG in this state, the temperature at the time of transportation in terms of heat dissipation is minus 104 ° C for the minus 162 ° C of LNG, and the pressure during transportation is also the same for LNG and ethylene Because of atmospheric pressure, both temperature management and pressure management are sufficient. However, since the ethylene is 0.57 in the liquid ratio with respect to 0.5 or less in the liquid ratio when the LNG is transported, the tank strength is insufficient.

Further, due to the difference among the liquids, when the ship is loaded in this state, the center of the entire ship at the time of transportation rises, and the restoration performance (stability) for the lateral slope necessary for the operation becomes insufficient. In other words, there is a problem that it is difficult to use as a medium-sized liquefied gas carrier having many opportunities to transport many kinds of multi-gas because it can not transport ethylene or the like in the LNG carrier.

Regarding the method of designing the liquefied gas transportation line, for example, when designing a liquefied gas carrier of a MOSS type dedicated to LNG, the width of the hull must always be designed to be the same, and the LNG tank heat- However, when designing a liquefied gas carrier for exclusive use of ethane, maximize the tank volume by increasing the tank diameter as much as the thickness of heat dissipation is reduced. In order to maximize the tank capacity, a liquefied gas transport line for transporting the liquefied gas for each specific type is designed such that the equatorial portion of the MOSS type spherical tank is increased as far as the stability of the main line allows, The design is carried out in accordance with the characteristics of the dedicated liquefied gas. Therefore, in the case of multi-cargo such as LNG / LPG / ethane / ethylene, determination of each design item corresponding to which liquefied gas is a big problem.

Prior art literature

Patent literature

Patent Document 1: Japanese Patent Application Laid-Open No. 6-123569

Summary of the Invention

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances and an object of the present invention is to provide a method for efficiently transporting liquefied gas not only in LNG but also in multi-gas such as LPG, ethane, ethylene, And a method of designing a liquefied gas transportation line.

The liquefied gas transit line for achieving the above object is a liquefied gas transit line equipped with a MOSS type low temperature liquefied gas tank, wherein the total loading capacity of the low temperature liquefied gas tanks is 60,000 m 3 to 90,000 m 3, Wherein the low-temperature liquefied gas tank has a heat dissipation structure for LNG, and the structural strength of the low-temperature liquefied gas tank and the structural strength of the cargo hold on which the low-temperature liquefied gas tank is mounted are LNG or ethane or ethylene or LPG The liquefied gas tank is made of structural strength and the hull structure is constructed such that when LNG is mounted on the entirety of the low temperature liquefied gas tank or when ethane or ethylene or LPG is mounted on the entirety of the low temperature liquefied gas tank, When the gas tank is mixed with a plurality of LNG, ethane, ethylene, and LPG, Restore server configuration is equipped with a performance on.

According to this configuration, since the total loading capacity of the low-temperature liquefied gas tanks is 60,000 m 3 or more and 90,000 m 3 or less, it is possible to improve the efficiency of medium-scale and short-distance transportation of the liquefied gas by the liquefied gas transportation line .

Further, since the MOSS-type low-temperature liquefied gas tank which is difficult to cause sloshing and can be transported in a semi-mounted state is mounted, by adopting this MOSS-type low-temperature liquefied gas tank, You can solve the problem. As a result, in the liquefied gas transportation line of the conventional membrane type tank, it is possible to operate in the tank reclaimed state which was impossible due to sloshing, and a small amount of unloading in a plurality of ports becomes possible.

Regarding the heat dissipation structure of this low temperature liquefied gas tank, a heat dissipation structure for LNG that can correspond to a minus 162 캜 temperature at the time of transportation becomes a heat dissipation structure effective also for ethylene having a temperature of minus 104 캜 at the time of transportation.

In addition, in particular, in the case where mixing is possible, the structural strength of this MOSS type low-temperature liquefied gas tank is a factor of the liquid ratio at the time of transportation. Therefore, it is desirable that the LNG, , 0.55 of the liquid ethane of the larger one or 0.57 of the liquid fertilizer of the ethylene. In addition, the strength of the liquid is such that the LNG can be handled in the fully loaded state and the unloaded state of the other LNG, ethane or ethylene. This makes it possible to load and transport both LNG and ethane or ethylene into the low-temperature liquefied gas tank of the MOSS type, so that the conditions for pressure, boiling point and specific gravity during transportation are relaxed or equivalent LPG It is possible to mount and transport each of them using the same technique.

In addition, the strength of the ship which supports the low-temperature liquefied gas tank of the MOSS type has sufficient strength in correspondence with LNG in terms of temperature, and it is sufficient that even in the state of mounting the high specific gravity ethane or ethylene or LPG, Temperature liquefied gas tank of the low-temperature liquefied gas tank.

With respect to the hull, it is possible to secure the draft required for navigation even when LNG having a relatively small specific gravity is mounted, and even when ethane or ethylene or LPG having relatively heavy specific gravity is mounted, It is possible to secure the performance and stability of the hull at the same time as maintaining free performance and restoration performance even when a plurality of LNG, ethane, ethylene and LPG having different specific gravity are mixed together. Make it possible to trim. These ensure the capacity of the ballast water tanks, and the arrangement of the ballast water tanks and the shape of the hull, and are sufficiently possible within the range of the prior art.

The combination of these MOSS type low-temperature liquefied gas tanks, LNG heat dissipation structure, structural strength of LNG or ethane or ethylene or LPG tank, structural strength of cargo hold, and LNG, ethane, ethylene, The liquefied gas transportation line capable of mounting a medium-scale multi-gas having a total capacity of 60,000 m 3 to 90,000 m 3 of the low-temperature liquefied gas tanks is obtained.

That is, the structural strength of the transportation scale, the MOSS type low temperature liquefied gas tank, the structure strength of the low temperature liquefied gas tank corresponding to the multi gas and the structure strength of the cargo hold, the structural strength of the hull structure corresponding to the multi gas, By combining the securing of the restoration performance, it is possible to efficiently transport medium-sized liquefied gas and to engage in medium-scale liquefied gas transportation for transporting liquefied gas of not less than 60,000 m 3 and not more than 90,000 m 3, It becomes possible to provide a liquefied gas transportation line.

In other words, this liquefied gas transportation line can carry low-temperature liquefied gas such as LNG, ethane, ethylene, LPG, etc., and can be used as a dedicated line for each liquefied gas. Further, Or it can be installed in a multi gas carrier which can be changed in accordance with the use of the liquefied gas.

In the liquefied gas transporter having the above configuration, when the number of the low-temperature liquefied gas tanks is three and the volume of the tank per unit is 20,000 m 3 to 30,000 m 3, the number of tanks is three, , And it is also possible to carry out a small cargo unloading in a consuming place at the time of medium scale transportation efficiently.

In the liquefied gas carrier having the above configuration, the cargo machinery room is disposed in front of the low-temperature liquefied gas tank at the foremost part, and the cargo machinery room is provided at one or several of the respective low- Or a piping connection manifold for connecting the piping on the side of the maritime unloading equipment is disposed, the following effects can be obtained.

In the case of three liquefied gas transit lines of the MOSS type, if the cargo machine room is disposed between the tanks as in the conventional method, the proper arrangement of the manifold suitable for the pipelines on the land or offshore bases is hindered. , The cargo machine room is not located between the low-temperature liquefied gas tanks, but on the front part of the low-temperature liquefied gas tank (the first tank) at the foremost part, and the piping connection manifold is disposed between the low- It is possible to increase the consistency with the offshore or offshore loading and unloading facilities by arranging one or several or all of them.

Further, since the cargo machine room is arranged in the narrow part between the low-temperature liquefied gas tanks, compared with the conventional technology in which the one-storey part of the cargo machine room has a three-story building structure as the passage space in front and rear, Since the machine room is located at the front of the low-temperature liquefied gas tank (No. 1 tank) at the foremost part, the entire width of the deck can be used. Therefore, it is possible to suppress the height of the installation by making the passage space to the left and right while making the structure of one or two floors, thereby making it possible to reduce the wind pressure resistance and lower the center.

The method for designing a liquefied gas transportation line for achieving the above object is a method for designing a liquefied gas transportation line having a MOSS type low temperature liquefied gas tank mounted thereon, wherein the total storage capacity of the low temperature liquefied gas tanks is 60,000 m 3 to 90,000 m 3 And the structural strength of the low-temperature liquefied gas tank and the structural strength of the cargo hold on which the low-temperature liquefied gas tank is mounted are set to be LNG or ethane Or a structural design for ethylene or LPG, and a hull structure in which, when LNG is mounted on the whole of the low temperature liquefied gas tank, ethane or ethylene or LPG is mounted on the entire low temperature liquefied gas tank , Or in the case where a plurality of LNG, ethane, ethylene, and LPG are mixed in the low-temperature liquefied gas tank Is a method of designing a liquefied gas transport ship having a hull, characterized in that the design process.

That is, in the case of making it possible to mix particularly, the MOSS type cargo tank is designed to satisfy the correspondence to the extremely low temperature of the LNG, and also to satisfy the correspondence in loading of ethane or ethylene or LPG at high boiling point, It is designed to be compatible. This liquefied gas transporting line is capable of transporting low-temperature liquefied gas such as LNG, ethane, ethylene, LPG and the like, and can be used as a dedicated line for each liquefied gas. Further, a liquefying apparatus and a gas processing apparatus So that it can be used as a multi-gas carrier which can change the loading depending on the type of liquefied gas.

In the method for designing a liquefied gas transportation line having the above configuration, the tank designing step may be carried out such that the number of the low temperature liquefied gas tanks to be mounted is three, the tank capacity per unit is 20,000 m 3 to 30,000 m 3, The liquefied gas transportation line capable of efficiently carrying out a small amount of discharge in a consuming place at the time of medium-scale transportation while maintaining a high transportation efficiency with three tanks, Can be efficiently designed.

In the method for designing the liquefied gas transportation line, it is preferable that the hull designing process is such that the low-temperature liquefied gas tank of the existing LNG having the MOSS type low-temperature liquefied gas tank of 125,000 m 3 to 135,000 m 3 It is not necessary to newly design the MOSS type low-temperature liquefied gas tank again to construct the liquefied gas transportation line efficiently, Can be designed.

In the method for designing the liquefied gas transportation line, a cargo machinery room is disposed in front of the cryogenic liquefied gas tank at the foremost part, and one or a few or all of the cryogenic liquefied gas tanks are provided with land or sea water The piping connection manifold for connecting the piping on the side of the unloading equipment to the piping connection manifold for the piping connection on the side of the unloading equipment can be provided. So that the liquefied gas transporting line having the cargo machinery room whose center of gravity is lowered can be efficiently designed.

According to the method for designing the liquefied gas transportation line and the liquefied gas transportation line of the present invention, it is possible to efficiently transport the liquefied gas in the intra-regional transportation and the short-distance transportation, as well as the LNG and the multi gas such as ethane or ethylene, And it is possible to provide a liquefied gas transporting line having a releasable function.

Brief Description of Drawings

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic side view showing the configuration of a liquefied gas transportation line according to an embodiment of the present invention. FIG.

[Fig. 2] Fig. 2 is a diagram schematically showing a configuration of a method of designing a liquefied gas transportation line according to an embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a method of designing a liquefied gas transportation line and a liquefied gas transportation line according to the embodiments of the present invention will be described with reference to the drawings. In the following, description is made on ethylene as an object, but the present invention can be applied to the case where the liquid ratio of the liquid is changed from 0.57 of ethylene to 0.55 of ethane even in the case of using the liquid. Further, the present invention can be applied to LPG by correcting the appropriate boiling point and specific gravity.

First, a liquefied gas transporting line according to an embodiment of the present invention will be described. 1, this liquefied gas transportation line 1 has a MOSS-type low temperature liquefied gas tank 10 in a double bottom bottomed cargo hold 4 provided with a cargo hold bottom plate 3 on the bottom 2, Three are installed. The total capacity of the three low temperature liquefied gas tanks is 60,000 m 3 to 90,000 m 3, but the volume of the low temperature liquefied gas tanks 10 per tank is 20,000 m 3 to 30,000 m 3. This makes it possible to carry out a small amount of relief in a consumable area at a time of medium-scale transportation while maintaining a high transport efficiency with three tanks.

A propeller 5 and a key 6 are provided at the stern for navigation and an engine room 7 for accommodating a main engine (not shown) for driving the propeller 5 and an auxiliary machine On the engine room (7), there is installed an upper structure (8) in which a residence and a bridge are arranged. On the front side of the upper structure 8 is mounted on the cargo hold 4 in a state in which the upper part of the low temperature liquefied gas tank 10 having a spherical shape protrudes above the upper deck 9. [

In the present invention, the total capacity of the low-temperature liquefied gas tanks is set to 60,000 m 3 to 90,000 m 3, thereby forming a medium-scale liquefied gas transportation line. Therefore, the liquefied gas transportation line And it is possible to achieve efficiency in medium scale transportation.

Since the low temperature liquefied gas tank 10 employs the MOSS type liquefied gas tank which is less susceptible to sloshing and can be transported in the reclaimed state, it is possible to solve the sloshing problem caused by liquefied gas, The liquefied gas transportation line of the tank is capable of operating in a tank-unloaded state which was impossible due to sloshing, and a small amount of discharge can be made in a plurality of ports.

In the low temperature liquefied gas tank 10, a heat dissipation structure for LNG is provided. In other words, the heat-radiating structure for LNG capable of handling at a temperature of minus 162 ° C at the time of transportation becomes a heat-radiating structure that is effective also for ethylene having a temperature of minus 104 ° C during transportation.

The liquefied gas tank 10 is structured so as to have a structural strength allowing ethylene to be mounted thereon. That is, since the structural strength of the MOSS type low-temperature liquefied gas tank 10 is a factor (factor) during transportation, the ratio of the liquid ratio at the time of transport of LNG and ethylene to the high- (Or 0.55 in the case of ethane). Further, it is assumed that the strength is such that it is possible to cope with both the full load condition and the unloaded condition with respect to both LNG and ethylene having different specific gravity. This makes it possible to mount both LNG and ethylene in the MOSS type low temperature liquefied gas tank 10. [

Further, the structural strength of the cargo hold (4) on which the low-temperature liquefied gas tank (10) is mounted is structured to have a structural strength permitting the mounting of ethylene. Thereby, the strength of the structure of the cargo hold 4 is set to a strength that can be handled even in the full load state of ethylene.

Regarding the hull structure, the strength of the hull supporting the low temperature liquefied gas tank of the MOSS type is set to a hull structure having sufficient strength corresponding to LNG in terms of temperature and sufficient And the hull structure having the total strength is made.

With respect to the hull, in the case where LNG having a relatively small specific gravity is mounted on the entirety of the low temperature liquefied gas tank 10, ethylene having a relatively high specific gravity is mounted on the entire low temperature liquefied gas tank 10, or In the case of three cases where LNG and ethylene are mixed in the low-temperature liquefied gas tank (10), the restoration performance for the freeboard and the transverse inclination sufficient for each of the navigations is configured.

This makes it possible to secure the draft required for navigation even when LNG having a relatively light specific gravity is mounted, and even when ethylene having a relatively heavy specific gravity is loaded, the freeboard and restoration performance (stability) required for navigation It is possible to make the trim (longitudinal slope) of the hull to be a trim suitable for navigation even when the LNG having different specific gravity and ethylene are mixed together. That is, even when only relatively lightweight LNG is loaded, sufficient stability is ensured even when only ethylene having a relatively heavy specific gravity is loaded, and also when LNG and ethylene are mixed, thereby making it possible to navigate safely. These configurations are sufficient to secure the capacity of the ballast water tank, to arrange the ballast water tank and to set the shape of the hull, and can be sufficiently constituted by conventional well-known techniques.

According to the liquefied gas carrier 1 having the above structure, the LNG heat radiation structure in the MOSS type low temperature liquefied gas tank 10, the low temperature liquefied gas tank 10, the structural strength of the low temperature liquefied gas tank 10 for ethylene, The total loading volume of the low-temperature liquefied gas tanks is set to be not less than 60,000 m 3 and not more than 90,000 m 3 by combining the structural strength of the hold 3 for ethylene and the hull structure capable of coping with both of LNG and ethylene, It becomes a medium-sized liquefied gas transportation line, and multi-gas can be loaded to efficiently transport.

That is, by the combination of the transportation scale, the MOSS type low-temperature liquefied gas tank, the structural strength of the tank corresponding to the multi-gas, the structural strength of the cargo hold, the structural strength of the hull structure and securing of the draft, It is possible to provide a liquefied gas transportation line capable of engaging in medium-scale liquefied gas transportation that transports liquefied gas of 60,000 m 3 to 90,000 m 3, which is capable of efficiently transporting medium-sized liquefied gas and loading and unloading in a plurality of ports Do.

In other words, this liquefied gas transportation line can be used as a dedicated line for each liquefied gas by carrying low-temperature liquefied gas such as LNG, ethane, ethylene, LPG, etc., It is possible to cope with the use of a multi-gas carrier which can change the loading depending on the use of the liquefied gas.

Further, as shown in Fig. 1, a cargo machine room (a part painted with no clearance) 11 is disposed in front of the foremost low-temperature liquefied gas tank 10. In addition to this, one or a few or all of each of the low-temperature liquefied gas tanks 10 (at two positions (four positions in the positive direction) between the positions in FIG. 1) A piping connection manifold (cross hatching portion) 12 for connecting piping is disposed.

As a result, in the case of three liquefied gas transportation lines of the MOSS type, if the cargo machine room is disposed between the tanks as in the conventional method, there is a problem that the proper placement of the manifold suitable for the piping It is possible to increase the compatibility with the landing or maritime landing equipment side.

In addition, since the cargo machine room is arranged in the narrowed portion between the low-temperature liquefied gas tanks in the prior art, the one-storey portion of the cargo machine room can not be made into a three-story building structure as the passage space at the front and rear, And the height of the center height is increased so that the cargo machine room 11 can be constructed in a one or two-story building structure with the passage space being secured to the left and right by using the full width of the upper deck 9, It is possible to reduce the wind pressure resistance and lower the center of gravity.

Next, a method of designing a liquefied gas transporting line according to an embodiment of the present invention will be described. This design method of the liquefied gas transportation line is a design method of the liquefied gas transportation line 1 on which the MOSS type low temperature liquefied gas tank 10 is mounted. As shown in Fig. 2, in the process of this designing method, The designing step S1 of the hull designing step S10 is composed of a tank designing step S10, a tank designing step S20 and a hull designing step S30.

In this tank designing step S10, the total capacity of the low-temperature liquefied gas tanks 10 is 60,000 m 3 to 90,000 m 3, and the heat radiation specification of the low-temperature liquefied gas tank 10 is LNG . The structure strength of the low temperature liquefied gas tank 10 and the structural strength of the cargo hold 4 on which the low temperature liquefied gas tank 10 is mounted are designed as the structural strength for ethylene do.

That is, the MOSS type low-temperature liquefied gas tank 10 is designed to satisfy the correspondence of cryogenic temperature of LNG and to cope with thermal shrinkage and high load so as to satisfy the correspondence of loading of high-density of ethylene. This liquefied gas transport line 1 can be used as a dedicated line for transporting liquefied gas such as LNG, LPG, ethane or ethylene, and can also be used as a dedicated line for liquefied gas, It is possible to cope with the use as a multi-gas carrier which can change the dropping depending on the kind of the liquefied gas.

The tank designing step S10 includes a tank volume determining step S11 for designing the tank with the number of mounts of the low-temperature liquefied gas tank 10 being three, the tank volume per unit being not less than 20,000 m 3 and not more than 30,000 m 3, It is possible to design a liquefied gas transportation line capable of carrying out a small amount of discharge in a consuming place at medium size transportation while maintaining a high transportation efficiency by setting the number of tanks to three, can do.

In addition, in the tank designing step S20, the cargo machinery room 11 is disposed in front of the foremost low temperature liquefied gas tank 10, and one or several of each of the low temperature liquefied gas tanks 10 Or the entire piping connection manifold 12 for connecting the piping on the land or sea side of the cargo handling equipment to the entire piping (in FIG.

As a result, the piping connection manifold 12, which has increased compatibility with the off-shore or off-shore installation equipment side, and a one-layer or two-layer structure while securing the passage space on both sides, And the liquefied gas transportation line having the cargo machinery room 11 whose center is lowered can be efficiently designed. Further, the tank designing process 20 may be included in the tank designing process S10 or the hull designing process S30.

In the hull designing process S30, when the LNG is mounted on the entire low-temperature liquefied gas tank 10, when the entirety of the low-temperature liquefied gas tank 10 is loaded with ethylene, or when the liquefied gas tank 10) are designed to operate in the three cases where LNG and ethylene are mixed.

In the hull designing process S30, for example, a low-temperature liquefied gas tank 10 having a capacity of 125,000 m 3 or more and 135,000 m 3 or less is connected to a low-temperature liquefied gas tank 10 of a conventional LNG having 4 to 5 units. And a conventional tank utilization step S31 for designing the hull structure to match the low temperature liquefied gas tank 10 of the existing LNG line on the assumption that the hull structure is removed and reused and mounted. Thereby, there is no need to newly design the MOSS type low temperature liquefied gas tank 10 again, and the liquefied gas transportation line 1 can be designed efficiently.

Industrial availability

According to the design method of the liquefied gas transportation line and the liquefied gas transportation line of the present invention, it is possible to efficiently transport the liquefied gas in the inland transportation and the short-distance transportation, as well as the LNG, the multi gas such as LPG, It is possible to use a large number of medium-volume liquefied gas transportation lines because it can provide a liquefied gas transportation line having a function capable of dropping and unloading.

Explanation of symbols

1 liquefied gas carrier

2 bottoms

3 Hold bottom

4 Cargo hold

5 Propeller

6 keys

7 engine room

8 Superstructure

9 upper deck

10 Low temperature liquefied gas tank

11 Cargo Machine Room

12 Piping connection manifold

Claims (7)

As a liquefied gas transportation line equipped with a MOSS type low temperature liquefied gas tank,
The total volume of the low temperature liquefied gas tanks is set to 60,000 m 3 to 90,000 m 3,
Wherein said low temperature liquefied gas tank is configured to have a heat dissipation structure for LNG,
The structural strength of the low-temperature liquefied gas tank and the structural strength of the cargo hold equipped with the low-temperature liquefied gas tank are structured to allow the mounting of LNG, ethane, ethylene, or LPG,
In the case where LNG is mounted on the entirety of the low-temperature liquefied gas tank, the hull structure is constructed such that when all of the low-temperature liquefied gas tank is loaded with ethane, ethylene or LPG, or when the low- temperature liquefied gas tank is filled with LNG, , Or a case in which a plurality of LPGs are mixed, is constructed so as to have sufficient restoration performance for freeboard and transverse inclination, respectively, in navigation when operated. The method according to claim 1,
Wherein the number of the low-temperature liquefied gas tanks is three, and the tank volume per unit is 20,000 m 3 to 30,000 m 3. The method according to claim 1 or 2,
And a piping connection manhole for connecting piping on land side or off-shore piping side to one, several or all of the low-temperature liquefied gas tanks, respectively, Wherein a fold is disposed. As a design method of a liquefied gas transportation line equipped with a MOSS type low-temperature liquefied gas tank,
Wherein the total volume of the low-temperature liquefied gas tanks is 60,000 m 3 or more and 90,000 m 3 or less, the heat radiation specification of the low-temperature liquefied gas tank is a heat radiation specification for LNG, A tank designing step of designing the structural strength of the cargo hold equipped with the low-temperature liquefied gas tank as the structural strength for LNG, ethane, ethylene, or LPG;
When liquefied natural gas (LNG) is mounted on the entirety of the low-temperature liquefied gas tank, when the liquefied gas tank is filled with ethane, ethylene or LPG, or LNG, ethane, ethylene, LPG And a hull designing step of designing the hull designing operation so that the hull designing operation can be carried out in each of the three cases. 5. The method of claim 4,
Wherein the tank designing step includes a tank volume determining step of designing the low temperature liquefied gas tank by setting the number of the low temperature liquefied gas tanks to three and setting the volume of the tank per tank from 20,000 m 3 to 30,000 m 3 A method for designing a liquefied gas carrier. The method according to claim 4 or 5,
It is preferable that the hull designing process is such that the low-temperature liquefied gas tank of the existing LNG having the MOSS type low-temperature liquefied gas tank of 125,000 m 3 or more and 135,000 m 3 or less is removed and mounted, And a tank utilization process that is designed in accordance with a liquefied gas tank. The method according to any one of claims 4 to 6,
The liquefied gas tank is disposed in front of the low-temperature liquefied gas tank at the foremost part, and at least one of the low-temperature liquefied gas tanks is connected to the piping at the land side or the off- And a tank peripheral design process for placing a manifold.

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