JP5863900B2 - Liquefied gas transport ship and design method of liquefied gas transport ship - Google Patents

Description

  The present invention relates to a medium-volume liquefied gas transport ship having a medium capacity of 60,000 to 90,000 square meters suitable for short-distance transport and coastal secondary transport, and a design method for a liquefied gas transport ship.

LNG ships carrying LNG (liquefied natural gas) are becoming larger and larger, but it is expected that the number of large LNG ships will increase in the future. In the transport of LNG, the main component of LNG is methane (CH ₄ ), the pressure during transport in the liquid state of LNG is atmospheric pressure, the temperature is minus 162 ° C., and the liquid specific gravity of the main component of methane is Is 0.43, but the liquid specific gravity is 0.43 to 0.48 due to the compositional component ratio of LNG. Therefore, a heat insulating structure such as a heat insulating layer is provided to keep the tank at a low temperature. Moreover, since the specific gravity of liquefied natural gas is very light at 0.5 or less, the tank volume is large for the hull.

  In recent years, ship transportation of LNG has become necessary for short-distance transportation by ship and secondary transportation in the coastal area. In particular, LNG receiving land tanks in Japan have sizes ranging from 60,000 cubic meters to 90,000. There are a lot of standing rice, and in response to this, there are actually medium-sized LNG ships of 60,000 to 90,000 square meters, but the membrane type LNG ships are mainly in service. is there.

  However, this membrane-type tank is vulnerable to sloshing, and is not allowed to operate in a semi-loading state where sloshing is a concern. The medium-scale liquefaction of 60,000 to 90,000 square meters used for short-distance transportation such as secondary transportation within the region is not possible. There is a problem that it is not suitable for gas transport ships.

As an anti-sloshing measure, the adoption of a MOSS type low temperature liquefied gas tank is conceivable and the transport scale is not described, but an LNG ship having 3 to 5 MOSS type low temperature liquefied gas tanks is disclosed (for example, , See Patent Document 1.)
On the other hand, there are cases where medium-scale liquefied gas transportation is carried out exclusively for LNG, but in recent years, not only LNG but also ethane (C ₂ H ₆ ) and ethylene (C ₂ H ₄ ) are used for applications. It is coming. Therefore, it has been required from the aspect of efficient use of liquefied gas transport ships that ethane and ethylene can be transported in addition to transport of LNG and LPG.

  However, with regard to LPG (liquefied petroleum gas), there is a track record of the same medium-sized LPG ship, and ethylene has a track record of operating an ethylene ship with an ethylene loading weight of 3,500 tons, but depending on the situation, LNG, LPG A medium-sized liquefied gas transport ship that can carry and transport multigas such as ethane and ethylene on the same liquefied gas transport ship has not yet been manufactured.

  This LPG is a gas fuel containing propane, butane or the like as a main component and is liquefied at a relatively high temperature even under atmospheric pressure, is heavier than LNG, and has a larger amount of heat per unit volume than LNG. For example, under atmospheric pressure (about 1.0 atm), butane liquefies at minus 0.5 ° C. to minus 11.7 ° C., and propane liquefies at minus 42.1 ° C.

  Ethane is a component of natural gas that is the second most abundant component of methane, and is also obtained from petroleum gas as a by-product during oil production. The boiling point of ethane is minus 89 ° C. at normal pressure, and the specific gravity of the liquid is 0.55. The boiling point of ethylene is minus 104 ° C. at normal pressure, and the specific gravity during transportation is 0.57. The temperature and pressure during transportation of this ethylene in a liquid state are minus 104 ° C. and 0.1 MPa (about 1.0 atm).

  If this ethylene is to be mounted on an LNG ship as it is, the temperature during transportation is minus 104 ° C for LNG in terms of heat protection, and minus 104 ° C for ethylene, and the pressure during transportation is both LNG and ethylene. Since it is normally atmospheric pressure, both temperature management and pressure management are sufficient, but ethylene has a liquid specific gravity of 0.57 or less compared to a liquid specific gravity of 0.5 or less during LNG transportation. Insufficient to mount and transport.

  In addition, due to the difference in liquid specific gravity, if it is installed as it is, the center of gravity of the entire ship at the time of transportation rises, and the restoration performance (stability) related to the lateral inclination necessary for operation will be insufficient. In other words, the LNG carrier can not transport ethylene and the like, and there is a problem that it is difficult to use it as a medium-scale liquefied gas carrier with many opportunities to transport many types of multi-gas.

  As for the design method for the liquefied gas transport ship, for example, when designing a MOSS type liquefied gas transport ship dedicated for LNG, the hull width should always be the same and the LNG tank thermal insulation can be equipped. The tank diameter is determined, but when designing a liquefied gas carrier dedicated to ethane, the tank diameter is increased to maximize the tank volume by reducing the heat insulation thickness. In addition, in order to maximize the tank volume, the liquefied gas that transports the liquefied gas for each special type, such as extending the equator of the MOSS type spherical tank to maximize it as long as the ship's stability allows. When designing a transport ship, it is designed according to the characteristics of the dedicated liquefied gas, so in the case of multi cargo such as LNG / LPG / ethane / ethylene, which liquefied gas each design item corresponds to. Deciding is a big issue.

Japanese Patent Laid-Open No. 6-123569

  The present invention has been made in view of the above situation, and the purpose thereof is not only LNG but also multi-gas such as LPG, ethane, ethylene, etc. Another object of the present invention is to provide a liquefied gas transport ship having a function capable of loading and unloading at a plurality of ports, and a design method for the liquefied gas transport ship.

A liquefied gas transport ship for achieving the above object is a liquefied gas transport ship equipped with a MOSS type low temperature liquefied gas tank. The total mounted volume of the low temperature liquefied gas tank is 60,000 m ³ or more and 90,000 m ³ or less. And the low-temperature liquefied gas tank is configured to have a thermal insulation structure for LNG, and the structural strength of the low-temperature liquefied gas tank and the structural strength of the cargo hold in which the low-temperature liquefied gas tank is mounted are LNG, ethane, ethylene, or When the structure of the hull structure is configured to allow the mounting of LPG and the hull structure is mounted with LNG in all of the low-temperature liquefied gas tank, when ethane or ethylene or LPG is mounted in all of the low-temperature liquefied gas tank, or Among the LNG, ethane, ethylene, and LPG in the low temperature liquefied gas tank In no event of three in the case of mixed plural, while ensuring the volume of the ballast water tanks, by setting the arrangement and the hull shape of the ballast water tanks, respectively sufficient freeboard and heel navigable when operated It is configured to have the restoration performance against.

According to this configuration, the total installed volume of the low-temperature liquefied gas tank is set to 60,000 m ³ or more and 90,000 m ³ or less, and this medium-sized liquefied gas transport ship improves the efficiency of medium-scale and short-distance transportation of liquefied gas. Can be achieved.

  Further, since a MOSS type low temperature liquefied gas tank that is less likely to cause sloshing and can be transported in a semi-mounted state is mounted, the use of this MOSS type low temperature liquefied gas tank can solve the sloshing problem caused by the liquefied gas liquid. As a result, the liquefied gas transport ship of the membrane type tank according to the prior art can be operated in a semi-loading state that cannot be performed due to sloshing, and a small amount can be unloaded at a plurality of ports.

  With regard to the heat insulation structure of this low-temperature liquefied gas tank, by adopting a heat insulation structure for LNG that can accommodate a temperature of minus 162 ° C. during transportation, a heat insulation structure that is effective against ethylene having a temperature of minus 104 ° C. Become.

  Also, especially when mixed loading is possible, the structural strength of the MOSS type low-temperature liquefied gas tank is a large factor in the liquid specific gravity during transportation of LNG and ethane or ethylene because the liquid specific gravity during transportation is a large factor. The ethane has a structural strength with respect to the liquid specific gravity of 0.55 or ethylene liquid specific gravity of 0.57. Moreover, it is set as the intensity | strength which can respond also to the full load state and semi-load state of LNG and ethane or ethylene from which liquid specific gravity differs. As a result, both LNG and ethane or ethylene can be mounted and transported in this MOSS type low-temperature liquefied gas tank, and the conditions for pressure, boiling point and specific gravity during transportation can be eased or comparable. LPG can be mounted and transported using the same method.

  In addition, the strength of the hull that sails in support of the MOSS-type low-temperature liquefied gas tank has sufficient strength to support LNG in terms of temperature, and even in a state where ethane or ethylene or LPG having a large specific gravity is mounted, It shall be strong enough to sail with the MOSS type low temperature liquefied gas tank supported.

  As for the hull, even when LNG with a relatively low specific gravity is installed, the draft required for navigation can be secured, and even when ethane or ethylene or LPG with a relatively high specific gravity is installed, In addition to ensuring dredging and stability (stability), even when multiple LNG, ethane, ethylene, and LPG with different specific gravity are mixed, drought and stability are secured, and the hull trim (vertical inclination) is secured. Make trim suitable for navigation. These are sufficiently possible within the range of the prior art by securing the capacity of the ballast water tank and setting the arrangement and hull shape of the ballast water tank.

These MOSS type low-temperature liquefied gas tanks, LNG thermal insulation structure, structural strength of tanks for LNG or ethane or ethylene or LPG, and structural strength of cargo hold, hull structure capable of co-mounting among LNG, ethane, ethylene and LPG This combination makes it possible to provide a liquefied gas transport ship capable of mounting a medium-scale volume multi-gas in which the total mounting volume of the low-temperature liquefied gas tank is 60,000 m ³ or more and 90,000 m ³ or less.

In other words, transport scale, MOSS type cryogenic liquefied gas tank, multi-gas compatible cryogenic liquefied gas tank structural strength and cargo hold structural strength, multi-gas compatible hull structural strength, and multi-gas compatible drought By transporting liquefied gas of 60,000 m ³ or more and 90,000 m ³ or less, which can support efficient transportation of medium-scale liquefied gas and loading and unloading at multiple ports through a combination of ensuring restoration performance It is possible to provide a liquefied gas transport ship that can engage in medium-scale liquefied gas transport.

  In other words, this liquefied gas transport ship transports low-temperature liquefied gases such as LNG, ethane, ethylene, LPG, etc., and can be used as a dedicated ship for each liquefied gas. By providing a processing apparatus permanently or additionally as needed, it becomes a structure which can respond also to using as a multi-gas carrier which can change a load according to the use of liquefied gas.

In the liquefied gas transport ship having the above configuration, when the number of low-temperature liquefied gas tanks is three and the tank volume per unit is 20,000 m ³ or more and 30,000 m ³ or less, the number of tanks is three and high. While maintaining the transportation efficiency, it is possible to navigate efficiently by carrying out a small amount of unloading at the consuming area for medium-scale transportation.

  In the liquefied gas transport ship having the above-described configuration, a cargo machine room is disposed in front of the foremost low-temperature liquefied gas tank, and one or some or all of the low-temperature liquefied gas tanks are loaded on land or offshore. If a manifold for connecting pipes for connecting piping on the facility side is arranged, the following effects are obtained.

  In a liquefied gas transport ship with three MOSS tanks, if the cargo machinery room is placed between tanks as in the conventional method, the proper placement of manifolds suitable for onshore or offshore base piping will be hindered. In the configuration, the cargo machine room is not located between the cryogenic liquefied gas tanks but at the front of the foremost cryogenic liquefied gas tank (No. 1 tank), and one or several manifolds for pipe connection are provided between the cryogenic liquefied gas tanks. Alternatively, by arranging all of them, it is possible to increase the consistency with the onshore or offshore cargo handling equipment side.

  Furthermore, since the cargo machine room is arranged in a narrow space between the low temperature liquefied gas tanks, this structure is compared with the conventional technology in which the first floor portion of the cargo machine room has a three-story structure as a front and rear passage space. Then, since the cargo machine room is arranged in front of the foremost low-temperature liquefied gas tank (No. 1 tank), the full width of the deck can be used. Therefore, it is possible to suppress the installation height by securing a passage space to the left and right, and to reduce the installation pressure by using a 1st to 2nd floor structure, thereby reducing the wind pressure resistance and lowering the center of gravity.

The liquefied gas transport ship design method for achieving the above object is a liquefied gas transport ship design method in which a MOSS type low temperature liquefied gas tank is mounted. The total mounted volume of the low temperature liquefied gas tank is 60,000 m ^3. more 90,000M ³ as well as below, and the insulation specifications of the low-temperature liquefied gas tank to the insulation specification for LNG, and the structural strength of the cargo hold for mounting the structural strength and the low-temperature liquefied gas tank of said low-temperature liquefied gas tank LNG or Tank design process designed with structural strength against ethane or ethylene or LPG and hull structure when LNG is installed in all of the low temperature liquefied gas tank, when ethane or ethylene or LPG is installed in all of the low temperature liquefied gas tank Or LNG or eta in the low temperature liquefied gas tank Emissions, ethylene, In no event three when embedded with a plurality of LPG, while securing the capacity of the ballast water tanks, by setting the arrangement and the hull shape of the ballast water tanks, to allow operations respectively It is a design method of a liquefied gas transport ship characterized by having a hull design process for designing.

  In other words, especially when mixed loading is possible, the MOSS type cargo tank can satisfy the response to the extremely low temperature of LNG and the response to the stacking of high specific gravity ethane or ethylene or LPG. Designed to handle heat shrinkage and high loads. This liquefied gas transport ship transports low-temperature liquefied gas such as LNG, ethane, ethylene, LPG, etc., and can be used as a dedicated ship for each liquefied gas, and if necessary, a liquefying device, By providing an additional gas processing device, it becomes a configuration that can be used as a multi-gas carrier that can change the load according to the type of liquefied gas.

In the design method of the liquefied gas transport ship having the above-described configuration, the tank design step may be performed by setting the number of low-temperature liquefied gas tanks to be three and the tank volume per unit being 20,000 m ³ or more and 30,000 m ³ or less. When configured to include a tank volume determination process for designing a low-temperature liquefied gas tank, it is possible to efficiently carry out a small amount of unloading at a consumption area during medium-scale transportation while maintaining high transportation efficiency with three tanks. It is possible to efficiently design a liquefied gas transport ship that can navigate.

The method of designing a liquefied gas transport ship, the hull design process, remove the low-temperature liquefied gas tank of an existing LNG carrier having said low-temperature liquefied gas tank of 125,000M ³ or more 135,000M ³ less MOSS type mounting If it is configured to include an existing tank utilization process in which the hull structure is designed in accordance with the low temperature liquefied gas tank of the existing LNG ship on the premise that it is to be done, there is no need to design a MOSS type low temperature liquefied gas tank again. In addition, a liquefied gas transport ship can be designed.

  In the above liquefied gas transport ship design method, a cargo machine room is disposed in front of the foremost low-temperature liquefied gas tank, and one or several or all of the low-temperature liquefied gas tanks are loaded on land or offshore. By configuring the tank peripheral design process to place a pipe connection manifold to connect the equipment side piping, the pipe connection manifold with increased consistency with the land or offshore cargo handling equipment side, and the passage space to the left and right In addition, it is possible to efficiently design a liquefied gas transport ship having a cargo machine room having a one- or two-story structure with reduced installation height, reduced wind resistance, and lowered center of gravity.

  According to the design method of the liquefied gas transport ship and the liquefied gas transport ship of the present invention, not only LNG but also multi-gas such as ethane or ethylene can be transported efficiently by intra-regional transport or short-range transport, and It is possible to provide a liquefied gas transport ship having a function capable of loading and unloading at a plurality of ports.

It is a side view which shows typically the structure of the liquefied gas transport ship of embodiment which concerns on this invention. It is a figure which shows typically the structure of the design method of the liquefied gas transport ship of embodiment which concerns on this invention.

  Hereinafter, a design method of a liquefied gas transport ship and a liquefied gas transport ship according to embodiments of the present invention will be described with reference to the drawings. In the following description, ethylene is described as an object, but even when ethane is the object, the present invention can be applied by replacing the liquid specific gravity from 0.57 of ethylene to 0.55 of ethane. Furthermore, the present invention can also be applied to LPG if an appropriate boiling point and specific gravity are corrected.

First, a liquefied gas transport ship according to an embodiment of the present invention will be described. As shown in FIG. 1, this liquefied gas transport ship 1 has three MOSS type low-temperature liquefied gas tanks 10 mounted on a double bottom cargo hold 4 in which a cargo hold bottom plate 3 is provided on a ship bottom 2. The total installed volume of these ^three low-temperature liquefied gas tanks is 60,000 m ³ or more and 90,000 m ³ or less, but the tank volume per unit of the low-temperature liquefied gas tank 10 is 20,000 m ³ or more and 30,000 m ³ or less. To do. As a result, the number of tanks is set to three so that high transportation efficiency can be maintained, and small-scale unloading can be efficiently performed at a consumption area for medium-scale transportation.

  The stern is provided with a propeller 5 and a rudder 6 for navigation, and further provided with a main engine (not shown) for driving the propeller 5 and an engine room 7 for housing auxiliary equipment. An upper structure 8 in which a residential area and a bridge are arranged is provided. The upper structure 8 is mounted in the cargo hold 4 in a state where the upper side of the spherical low-temperature liquefied gas tank 10 protrudes above the upper deck 9.

In the present invention, the total mounting volume of the low-temperature liquefied gas tank is set to 60,000 m ³ or more and 90,000 m ³ or less, so that it becomes a medium-sized liquefied gas transport ship. It becomes a good liquefied gas transport ship and can improve efficiency in medium-scale transport.

  Since the low temperature liquefied gas tank 10 employs a MOSS type liquefied gas tank that is less prone to sloshing and can be transported in a semi-mounted state, the sloshing problem due to the liquefied gas liquid can be solved, and the liquefied gas of the membrane type tank of the prior art A transport ship can be operated in a semi-loading tank, which was not possible due to sloshing, and small quantities can be unloaded at multiple ports.

  Moreover, in the low temperature liquefied gas tank 10, the heat insulation structure for LNG is given. In other words, by adopting a heat insulation structure for LNG that can cope with minus 162 ° C. during transportation, the heat insulation structure is effective against ethylene with minus 104 ° C. during transportation.

  At the same time, in particular, in the case where mixed loading is possible, the structural strength of the low-temperature liquefied gas tank 10 is set to a structural strength that allows mounting of ethylene. That is, the structural strength of the MOSS type low-temperature liquefied gas tank 10 is caused by the liquid specific gravity at the time of transportation, so the liquid specific gravity of the larger ethylene among the liquid specific gravity at the time of transport of LNG and ethylene is 0. 57 (note that 0.55 in the case of ethane) has a structural strength. Moreover, it is set as the intensity | strength which can respond also to each full load state and a half mounted state with respect to both LNG and ethylene from which specific gravity differs. As a result, both LNG and ethylene can be mounted on the MOSS type low-temperature liquefied gas tank 10.

  In addition, the structural strength of the cargo hold 4 on which the low-temperature liquefied gas tank 10 is mounted is configured to have a structural strength that allows mounting of ethylene. Thereby, the structural strength of the cargo hold 4 is set to a strength that can cope with a full state of ethylene.

  As for the hull structure, the hull that sails while supporting the MOSS type low-temperature liquefied gas tank has a sufficient hull structure that is compatible with LNG in terms of temperature. The hull structure has an overall strength.

At the same time, as for the hull, when LNG having a relatively low specific gravity is mounted on all of the low temperature liquefied gas tank 10, when ethylene having a relatively high specific gravity is mounted on all of the low temperature liquefied gas tank 10, or LNG is added to the low temperature liquefied gas tank 10. in no event and three in the case of mixed ethylene, while ensuring the volume of the ballast water tanks, by setting the arrangement and the hull shape of the ballast water tanks, respectively sufficient freeboard and transverse to the navigation during the flight It is configured so as to have stability for inclination.

  As a result, even when LNG with a relatively low specific gravity is installed, drafts necessary for navigation can be secured, and even when ethylene with a relatively heavy specific gravity is installed, the drought and stability performance (stability required for navigation) can be secured. ) And the trim (longitudinal inclination) of the hull can be made suitable for navigation even when LNG and ethylene having different specific gravities are mixedly loaded. In other words, even when only LNG with a relatively low specific gravity is installed, when only ethylene with a relatively high specific gravity is installed, or when LNG and ethylene are installed together, sufficient stability can be ensured and safe navigation is possible. Configure as follows. These configurations can be sufficiently configured by a well-known conventional technique by securing the capacity of the ballast water tank and setting the arrangement and hull shape of the ballast water tank.

According to the liquefied gas transport ship 1 having the above-described configuration, the MOSS type low temperature liquefied gas tank 10, the LNG heat insulation structure in the low temperature liquefied gas tank 10, the structural strength of the ethylene low temperature liquefied gas tank 10, and the structural strength of the ethylene cargo hold 4. , Medium-scale liquefied gas transport with a combined low-temperature liquefied gas tank capacity of 60,000 m ³ or more and 90,000 m ³ or less by combining hull structure, ballast water system and hull shape that can handle both LNG and ethylene It becomes a ship and can be delivered efficiently with multi-gas.

In other words, according to the combination of transport scale, MOSS type low temperature liquefied gas tank, multi-gas compatible structural strength, cargo hold structural strength, hull structural strength, and ensuring draft, trim and stability during voyage, Engage in medium-scale liquefied gas transportation that transports liquefied gas of 60,000 m ³ or more and 90,000 m ³ or less, which can efficiently transport liquefied gas of medium scale and load and unload at multiple ports A liquefied gas transport ship can be provided.

  In other words, this liquefied gas transport ship transports low-temperature liquefied gases such as LNG, ethane, ethylene, LPG, etc., and can be used as a dedicated ship for each liquefied gas. By providing a processing apparatus permanently or additionally as needed, it becomes a structure which can respond also to using as a multi-gas carrier which can change a load according to the use of liquefied gas.

  Further, as shown in FIG. 1, a cargo machine room (filled portion) 11 is disposed in front of the foremost low-temperature liquefied gas tank 10. At the same time, one or some or all of the low-temperature liquefied gas tanks 10 are connected to the land-side or off-shore cargo handling facility side piping (in FIG. 1 at all two locations between them (four locations on both sides)). A pipe connection manifold (cross-hatched portion) 12 to be connected is arranged.

  As a result, in a liquefied gas transport ship with three MOSS tanks, placing the cargo machine room between the tanks as in the conventional method will hinder proper placement of manifolds suitable for land or offshore base piping. This can solve the problem and increase the consistency with the onshore or offshore cargo handling equipment side.

  Furthermore, since the cargo machine room was arranged in the narrow space between the low-temperature liquefied gas tanks in the prior art, the first floor part of the cargo machine room had to be a three-story structure with the passage space to the front and back. Resolving the problem that the wind pressure resistance of the machine room increases and the height of the center of gravity increases, the cargo machine room 11 is secured to the left and right by using the full width of the upper deck 9, and from the first floor to the second floor. It is possible to reduce the installation height by using a floor structure, thereby reducing wind resistance and lowering the center of gravity.

  Next, a method for designing a liquefied gas transport ship according to an embodiment of the present invention will be described. This design method of the liquefied gas transport ship is a design method of the liquefied gas transport ship 1 equipped with the MOSS type low temperature liquefied gas tank 10, and as shown in FIG. 2, the steps of this design method, that is, the liquefied gas transport ship. The design process S1 includes a tank design process S10, a tank periphery design process S20, and a hull design process S30.

In this tank design step S10, the total mounting volume of the low-temperature liquefied gas tank 10 is set to 60,000 m ³ or more and 90,000 m ³ or less, and the heat-proof specification of the low-temperature liquefied gas tank 10 is set to the heat-proof specification for LNG. At the same time, in particular, when it is possible to perform mixed loading, the structural strength of the low temperature liquefied gas tank 10 and the structural strength of the cargo hold 4 in which the low temperature liquefied gas tank 10 is mounted are designed to be structural strength with respect to ethylene.

  In other words, the MOSS type low temperature liquefied gas tank 10 has a design capable of handling heat shrinkage and high load so as to satisfy the handling of LNG at a very low temperature and satisfy the handling of the high specific gravity of ethylene. To do. This liquefied gas transport ship 1 transports liquefied gases such as LNG, LPG, ethane, ethylene, etc., and can be used as a dedicated ship for each liquefied gas, and if necessary, a liquefier, By providing an additional gas processing device, it becomes a configuration that can be used as a multi-gas carrier that can change the load according to the type of liquefied gas.

The tank design process S10 includes a tank volume determination process S11 in which the number of low-temperature liquefied gas tanks 10 is set to three and the tank volume per unit is set to 20,000 m ³ or more and 30,000 m ³ or less. It is preferable that the liquefaction can be carried out by efficiently carrying out a small amount of unloading at a consumption area in the case of medium-scale transportation while maintaining high transportation efficiency with three tanks. A gas transport ship can be designed.

  Further, in the tank peripheral design step S20, the cargo machine room 11 is disposed in front of the foremost low-temperature liquefied gas tank 10, and one, some, or all of the low-temperature liquefied gas tanks 10 are arranged (in FIG. A piping connection manifold 12 for connecting piping on the land or offshore cargo handling equipment side is arranged.

  As a result, the piping connection manifold 12 with increased consistency with the onshore or offshore cargo handling equipment side and the passage space are secured on the left and right sides, and the installation height is reduced by reducing the installation height, and the wind pressure. It is possible to efficiently design a liquefied gas transport ship having a cargo machine room 11 with reduced resistance and a lowered center of gravity. In addition, you may comprise this tank periphery design process S20 so that it may be included in the tank design process S10 or the hull design process S30.

In the hull design process S30, the hull structure is configured such that LNG is mounted on all the low-temperature liquefied gas tanks 10, ethylene is mounted on all the low-temperature liquefied gas tanks 10, or LNG and ethylene are mixedly mounted on the low-temperature liquefied gas tanks 10. three in no event of case, while ensuring the volume of the ballast water tanks, by setting the arrangement and the hull shape of the ballast water tanks, are designed to be operated, respectively.

Further, in this hull design step S30, for example, to remove the low-temperature liquefied gas tank 10 of the existing LNG carrier, such as having to 4 to a low-temperature liquefied gas tank 10 of 125,000M ³ or more 135,000M ³ below MOSS type 5 group It is preferable to include an existing tank utilization step S31 in which the hull structure is designed in accordance with the low-temperature liquefied gas tank 10 of an existing LNG ship on the assumption that it is reused and mounted. As a result, there is no need to design the MOSS type low-temperature liquefied gas tank 10 again, and the liquefied gas transport ship 1 can be designed efficiently.

  According to the liquefied gas transport ship and the liquefied gas transport ship design method of the present invention, not only LNG but also multi-gas such as LPG, ethane, and ethylene can be transported efficiently by intra-regional transport or short-range transport. In addition, since a liquefied gas transport ship having a function capable of loading and unloading at a plurality of ports can be provided, it can be used for many liquefied gas transport ships having a medium capacity.

DESCRIPTION OF SYMBOLS 1 liquefied gas transport ship 2 ship bottom 3 cargo hold bottom plate 4 cargo hold 5 propeller 6 rudder 7 engine room 8 superstructure 9 upper deck 10 low temperature liquefied gas tank 11 cargo machine room 12 manifold for pipe connection

Claims (7)

A liquefied gas transport ship equipped with a MOSS type low temperature liquefied gas tank,
The total mounting volume of the low-temperature liquefied gas tank is 60,000 m ³ or more and 90,000 m ³ or less,
The low-temperature liquefied gas tank is configured to have a thermal insulation structure for LNG,
And the structural strength of the low-temperature liquefied gas tank and the structural strength of the cargo hold in which the low-temperature liquefied gas tank is mounted are configured to have a structural strength that allows mounting of LNG, ethane, ethylene, or LPG,
In addition, when the LNG is mounted on all of the low-temperature liquefied gas tanks, ethane, ethylene, or LPG is mounted on all of the low-temperature liquefied gas tanks, or LNG, ethane, ethylene, LPG is mounted on the low-temperature liquefied gas tanks. Oite the out multiple in case of three in the case of mixed, while ensuring the volume of the ballast water tanks, by setting the arrangement and the hull shape of the ballast water tanks, respectively sufficient freeboard and transverse to the navigation during the flight A liquefied gas transport ship configured to have a restoring performance against an inclination. 2. The liquefied gas transport ship according to claim 1, wherein the number of the low-temperature liquefied gas tanks is three and the tank volume per one is 20,000 m ³ or more and 30,000 m ³ or less.   A cargo machine room is arranged in front of the foremost low-temperature liquefied gas tank, and one or several or all of the low-temperature liquefied gas tanks are connected to pipes on the land or offshore equipment side. The liquefied gas transport ship according to claim 1, wherein a manifold is disposed. A method for designing a liquefied gas transport ship equipped with a MOSS type low temperature liquefied gas tank,
The total mounting volume of the low-temperature liquefied gas tank is set to 60,000 m ³ or more and 90,000 m ³ or less, the heat-proof specification of the low-temperature liquefied gas tank is set to the heat-proof specification for LNG, the structural strength of the low-temperature liquefied gas tank and the low temperature A tank design process in which the structural strength of the cargo hold in which the liquefied gas tank is mounted is designed to be structural strength with respect to LNG or ethane or ethylene or LPG;
When the LNG is mounted on all the low-temperature liquefied gas tanks, ethane or ethylene or LPG is mounted on all the low-temperature liquefied gas tanks, or a plurality of LNG, ethane, ethylene, and LPG are installed on the low-temperature liquefied gas tank. in no event the three in the case of mixed, while ensuring the volume of the ballast water tanks, by setting the arrangement and the hull shape of the ballast water tank, having a hull design process is operated each designed to be A design method for a liquefied gas transport ship. The tank design step includes a tank volume determination step of designing the low-temperature liquefied gas tank by setting the number of low-temperature liquefied gas tanks to be 3 and the tank volume per unit being 20,000 m ³ or more and 30,000 m ³ or less. The method for designing a liquefied gas transport ship according to claim 4. The hull design step, the low-temperature liquefied existing LNG carrier having a gas tank said low-temperature liquefied gas tank on the assumption that mounting remove the hull structure of the existing 125,000M ³ or more 135,000M ³ following MOSS type 6. The method for designing a liquefied gas transport ship according to claim 4 or 5, further comprising an existing tank using step for designing in accordance with the low temperature liquefied gas tank of the LNG ship.   A piping connection manifold that disposes a cargo machine room in front of the foremost low-temperature liquefied gas tank and connects one or several or all of the low-temperature liquefied gas tanks to the land or offshore cargo handling equipment side piping. The method for designing a liquefied gas transport ship according to any one of claims 4 to 6, further comprising a tank peripheral design step for arranging the tank.

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