JP7475315B2 - Liquefied gas fuelled ship - Google Patents

Description

The present invention relates to a liquefied gas fuelled ship.

Liquefied gas-fueled ships are ships that run on liquefied flammable gases such as LNG (Liquefied Natural Gas) and hydrogen. Liquefied gas-fueled ships emit less air pollutants during combustion compared to ships that run on heavy oil, and so are attracting attention as ships with a low environmental impact.

On the other hand, liquefied gas is extremely cold compared to heavy oil when stored in a liquid environment, so the piping must be made of expensive materials such as stainless steel, heat-insulated, various leak prevention measures must be implemented, and expansion joints must be used to prevent damage due to sudden thermal contraction, resulting in high equipment costs and the expense and effort required to maintain it. Furthermore, when loading liquefied gas fuel into a ship's hull, the handling of cryogenic liquid must be added to the handling of flammable gas, which not only places a practical burden on the crew, but also increases the amount of work required by adding pre-cooling work, and the psychological burden is also large due to the significant impact that a leak could have on the crew and the ship, making it an obstacle to active adoption.

On the other hand, in Patent Document 1, the LNG tank is configured to be detachable from the hull, thereby improving workability. However, even with this structure, extremely low-temperature liquefied gas still flows through the onboard piping, which still creates problems with workability.
As an example of a structure that improves the workability of a liquefied gas fueled ship, there is a structure in which a carburetor is attached to a liquefied gas tank to vaporize the liquefied gas, which is then supplied to an engine to drive the engine, generating electricity to drive a generator, and the generated electricity is used to drive an electric motor to rotate a propeller, and the carburetor and liquefied gas are unitized and the unit can be replaced, as in the liquefied gas fueled ship of Patent Document 2. However, in this structure, since the engine driven by liquefied gas is fixed inside the ship, only certain types of liquefied gas can be used as fuel. There are multiple types of liquefied gas, such as LNG and hydrogen, and the structure of the internal combustion engine such as the main engine and the structure of the liquefied gas supply system that supplies liquefied gas to the internal combustion engine change depending on the type. Therefore, when changing the type of liquefied gas used as fuel for self-propulsion in the structure of Patent Document 2, it is necessary to remove the engine fixed to the hull, and there was a problem that changing the fuel is effectively synonymous with changing to a new ship.
As a structure for improving the operability of a liquefied gas tank and a generator, a structure in which a liquefied gas tank and a generator are stored in a container such as a shipping container and are detachably attached to the hull is known, as in Patent Document 3. However, even with this structure, liquefied gas still flows through the piping inside the ship, so there are still problems with operability. In addition, the liquefied gas tank and the generator in Patent Document 3 are intended to supply power to other ships, and are not a propulsion mechanism for self-propulsion.

JP 2013-525169 A JP 2010-23776 A JP 2013-95257 A

As described above, in conventional liquefied gas fuelled ships, when cryogenic liquefied gas flows through onboard piping, there are problems such as high equipment costs, deterioration of operability and maintainability, and a burden on crew members.
In addition, conventional liquefied gas fueled ships have a propulsion mechanism fixed to the hull that is compatible with a specific type of liquefied gas, and are not designed to be able to propel themselves using multiple types of liquefied gas as fuel. Therefore, if the type of liquefied gas used as fuel for self-propulsion is changed, the propulsion mechanism, such as the internal combustion engine, fixed to the hull must be removed, and changing the fuel is effectively the same as changing to a new ship. However, due to the recent trend of reducing _CO2 emissions, multiple alternative fuel candidates with low _CO2 emissions have emerged, and an era is approaching when it will not be possible to decide on one type of fuel when building a new ship that will be used for more than 10 years.
The present invention has been made in consideration of the above-mentioned problems, and aims to provide a liquefied gas-fueled ship that requires less expensive equipment than conventional equipment, is easy to work with and maintain, does not unnecessarily increase the burden on crew members, and does not require a new construction or large-scale modifications when changing fuel.

In order to solve the above problems, the liquefied gas fuel ship of the present invention is a liquefied gas fuel ship equipped with an electric motor fixed to the hull and driving a propeller, a power supply unit that generates electricity to be supplied to the electric motor, a liquefied gas tank that stores liquefied gas as fuel for the power supply unit, a vaporizer that vaporizes the liquefied gas, and a fuel gas supply system that supplies the vaporized liquefied gas to the power supply unit, and is characterized in that it comprises a fuel container in which the liquefied gas tank and the vaporizer are mounted on a container frame, a fuel gas supply container in which the fuel gas supply system is mounted on a container frame, and a power generation container in which the power supply unit is mounted on a container frame, and the fuel container and the fuel gas supply container, and the fuel gas supply container and the power generation container are connected by onboard piping, which is a gas pipe through which the vaporized liquefied gas flows, and are detachably held by a holding mechanism provided on the hull.

In the present invention, the liquefied gas tank and vaporizer, the fuel gas supply system, and the power supply unit are each removably arranged on the hull as a container mounted on a container frame, and are connected by onboard piping, which is a gas pipe.
In this configuration, liquefied gas is supplied in a gaseous state from the liquefied gas tank to the ship's propulsion mechanisms, such as the fuel gas supply system and power supply unit, through the onboard piping. Therefore, there is no need to run cryogenic liquefied gas through the onboard piping, and work such as pre-cooling is not required. The fuel gas leakage prevention structure is not as complicated as that for liquefied gas piping, so workability is excellent and the practical and psychological burden on the crew is reduced. In addition, if you want to change the fuel to be used, you can simply replace the container equipped with the liquefied gas tank, power supply unit, and fuel gas supply system corresponding to the type of fuel on the hull, and there will be no impact on maintenance or on the crew's work or psychological burden due to the change in fuel.

The present invention provides a liquefied gas-fueled ship that can change fuels using less expensive equipment than conventional ships, has excellent workability and maintainability, and does not unnecessarily increase the burden on crew members, without the need for new construction or large-scale modifications.

FIG. 1 is a side view showing an overview of a liquefied gas fuelled ship according to a first embodiment, in which the deck and transverse bulkheads inside the ship are shown in cross section. FIG. 2 is an enlarged view of the engine compartment and its surroundings in FIG. 1 . FIG. 2 is a schematic diagram showing a connection structure between a fuel container and a fuel gas supply container. 1A and 1B are schematic diagrams of a twist lock mechanism, in which FIG. 1A shows the unlocked position and FIG. FIG. 13 is a diagram showing a modified example of the liquefied gas fuelled ship according to the first embodiment, showing at least one of a fuel container, a power generation container and a fuel gas supply container loaded on the exposed deck and held by cell guides. FIG. 13 is a diagram showing a modified example of the liquefied gas fuelled ship according to the first embodiment, showing a configuration in which a liquefied gas tank and a vaporizer are mounted on separate container frames. FIG. 13 is a diagram showing a modified example of the liquefied gas fuelled ship according to the first embodiment, showing a configuration in which a power generation container and a fuel gas supply container are mounted on the same deck within the ship. FIG. 13 is a diagram showing a modified example of the liquefied gas fuelled ship according to the first embodiment, illustrating a configuration in which a battery container for supplying power to an electric motor is mounted on the exposed deck of the hull. FIG. 11 is a diagram for explaining the procedures for loading a fuel container, a power generation container, and a fuel gas supply container onto the hull of a liquefied gas-fueled ship according to the first embodiment, showing the procedures for loading the fuel container and the procedures for transporting the power generation container from outside the ship to the fuel gas supply section inside the ship. FIG. 11 is a diagram for explaining the procedure for loading a fuel container, a power generation container, and a fuel gas supply container onto the hull of a liquefied gas fueled ship in the first embodiment, showing the procedure for transporting the power generation container from the fuel gas supply compartment to the power generation compartment. FIG. 11 is a diagram for explaining the procedures for loading a fuel container, a power generation container, and a fuel gas supply container onto the hull of a liquefied gas-fueled ship according to the first embodiment, where (a) shows the procedure for loading the power generation container into the power generation section, and (b) shows the procedure for transporting the fuel gas supply container from outside the ship onto the ship. FIG. 11 is a diagram for explaining the procedure for loading a fuel container, a power generation container, and a fuel gas supply container onto the hull of a liquefied gas-fueled ship according to the first embodiment, and shows the procedure for transporting the fuel gas supply container from outside the ship to the fuel gas supply section inside the ship. FIG. 11 is a side view of the liquefied gas fuelled ship according to the second embodiment, and is an enlarged view of the vicinity of the machinery compartment, showing a cross-sectional view of the deck and transverse bulkhead inside the ship. A diagram for explaining the procedure for loading a fuel container, a power generation container, and a fuel gas supply container onto the hull of a liquefied gas fueled ship related to the second embodiment, showing the procedure for transporting the power generation container into the fuel gas supply section. FIG. 11 is a diagram for explaining the procedure for loading a fuel container, a power generation container, and a fuel gas supply container onto the hull of a liquefied gas fueled ship according to the second embodiment, showing the procedure for transporting the power generation container from the fuel gas supply compartment to the power generation compartment. FIG. 11 is a diagram for explaining the procedure for loading a fuel container, a power generation container, and a fuel gas supply container onto the hull of a liquefied gas-fueled ship according to the second embodiment, showing the procedure for transporting the fuel gas supply container from outside the ship to the fuel gas supply section inside the ship. FIG. 13 is a diagram for explaining the procedure for loading a fuel container, a power generation container, and a fuel gas supply container onto the hull of a liquefied gas fueled ship according to a second embodiment, showing the procedure for loading the fuel container.

Preferred embodiments of the present invention will now be described in detail with reference to the drawings.
First, a schematic configuration of a liquefied gas fuelled ship 1 according to a first embodiment will be described with reference to Figures 1 and 2. Here, a cargo ship is exemplified as the liquefied gas fuelled ship 1.
As shown in Fig. 1, the liquefied gas fuelled ship 1 includes a hull 3. As shown in Fig. 2, the liquefied gas fuelled ship 1 also includes an electric motor 37, a power supply unit 78, a liquefied gas tank 55, a vaporizer 57, a fuel gas supply system 63 (Fuel Gas Supply System, FGSS), and a switchboard 45.

The hull 3 is a structural body that forms the hull of the liquefied gas fuelled ship 1, and is configured to enclose the interior of the ship with the ship bottom 5, side walls 7, and exposed deck 9, as shown in FIG. 1. The specific ship shape, hull structure, and arrangement of watertight bulkheads, etc. are appropriately set according to the application of the liquefied gas fuelled ship 1.

The liquefied gas fuelled ship 1 shown in Figure 1 illustrates a double bottom structure in which the ship bottom 5 has an outer outer bottom plate 5a that is in contact with the water outside the ship, and an inner bottom plate 21 that is provided above the outer bottom plate 5a and does not come into contact with the water outside the ship.
1 illustrates a structure in which three compartments, an engine compartment 11, a cargo compartment 13, and a bow compartment 15, are provided in this order from the stern side to the bow side. In this structure, the engine compartment 11 and the cargo compartment 13 are separated by a watertight transverse bulkhead, the engine room transverse bulkhead 17. The cargo compartment 13 and the bow compartment 15 are separated by a watertight transverse bulkhead, the cargo room transverse bulkhead 19.

The machinery space 11 is a space in which equipment necessary for propulsion of the liquefied gas fuelled ship 1 is installed. In Fig. 1, a deckhouse 33 is provided on the exposed deck 9 above the machinery space 11. The deckhouse 33 is a superstructure in which accommodation areas for the crew, a command center for maneuvering the ship, etc. are provided.
1 is divided into three compartments, in the order of a fuel gas supply compartment 27, a power generation compartment 29, and a propulsion compartment 31, from the exposed deck 9 toward the bottom of the ship 5 by the second deck 23 and the third deck 25 which are decks arranged inside. The third deck 25 is a deck arranged closer to the bottom 5 than the second deck 23.

A propeller 35 and a rudder 47 are provided at the stern end of the engine compartment 11. The propeller 35 is a thruster that rotates in the water about an axis in the X direction, which is the ship's longitudinal direction, to generate lift in the X direction and thereby propel the hull 3 in the X direction. The rudder 47 is an underwater plate that is provided behind the propeller 35 in the ship's longitudinal direction and can rotate about an axis in the Z direction, which is the vertical direction, and the course of the hull 3 can be changed by adjusting the angle of rotation.
In addition, instead of the rudder 47, an azimuth thruster may be used in which the propeller 35 rotates around an axis in the Z direction to change the course.

The cargo section 13 is a section in which the cargo to be transported by the liquefied gas fuelled ship 1 is loaded. The bow section 15 is a section in which a bow thruster (not shown) and an anchoring device (not shown) are installed, and is the section furthest to the bow of the hull 3 in the longitudinal direction of the ship.

The electric motor 37 is a motor that drives the propeller 35, and its rotating shaft is connected to the rotating shaft of the propeller 35 via a gear such as a reducer (not shown), and rotates the propeller 35 by transmitting power to the propeller 35. The electric motor 37 shown in FIG. 1 is fixed to the inner bottom plate 21 of the ship's bottom 5, which is the floor of the propulsion section 31. As long as the electric motor 37 can obtain an output that allows the liquefied gas fueled ship 1 to sail at the desired ship speed, its structure may be appropriately selected from known motors, including whether or not a reducer is required.

The power supply device 78 shown in FIG. 2 is a device that generates electric power to be supplied to the electric motor 37, and in FIG.
2 is a motor that generates power to be supplied to the electric motor 37 by converting mechanical energy into electrical energy through regenerative driving. The generator 77 is electrically connected to the electric motor 37 and supplies the generated power to the electric motor 37.

The internal combustion engine 75 is a heat engine that converts chemical energy into mechanical energy by burning fuel, and transmits this mechanical energy to the generator 77 to make the generator 77 generate electricity. An example of the internal combustion engine 75 is a reciprocating engine that uses the gas pressure of the combustion gas generated by combustion to move a piston up and down, converts the up and down movement into rotational motion using a crankshaft connected to the piston, and transmits the rotational force to the generator 77. An example of the internal combustion engine 75 is a gas turbine engine that uses the gas pressure of the combustion gas to rotate a turbine and transmits this rotational force to the generator 77. More specific structures and heat cycles of the internal combustion engine 75 vary depending on the type of fuel. When driven by gas fuel obtained by vaporizing liquefied gas such as LNG, the internal combustion engine 75 is a premixed combustion type in which the gas fuel is mixed with intake air in a pre-chamber of the combustion chamber such as an intake manifold (not shown) before being introduced into the combustion chamber. The structure is a reciprocating engine, the combustion method is ignition, and the heat cycle is mainly the Otto cycle. The internal combustion engine 75 driven by hydrogen gas is mainly a gas turbine engine, and the thermal cycle is mainly the Brayton cycle.

In FIG. 2, a structure for generating electricity by driving an internal combustion engine 75 using liquefied gas as fuel and regeneratively driving a generator 77 is illustrated as an example of the power supply device 78. However, as long as the device generates electricity using liquefied gas as fuel, the power supply device 78 is not limited to the combination of an internal combustion engine 75 and a generator 77. For example, if hydrogen is used as the liquefied gas, a fuel cell that generates electricity using hydrogen gas may be provided as the power supply device 78 instead of the internal combustion engine 75 and the generator 77. In the following explanation, unless otherwise specified, the first embodiment will be explained using a structure in which an internal combustion engine 75 and a generator 77 are combined as the power supply device 78.

The liquefied gas tank 55 is a container that stores liquefied gas, which is the fuel used to drive the internal combustion engine 75. The specific structure of the liquefied gas tank 55 can be selected as appropriate, so long as it can store liquefied gas in liquid form and has the strength to withstand damage caused by the rolling and vibration of the liquefied gas-fueled ship 1 while it is sailing. Note that liquefied gas here refers to flammable gas that is liquefied by lowering the temperature and pressure of a gas that is in gas form at room temperature.

The vaporizer 57 shown in FIG. 2 is a device that heats and vaporizes the gas in liquid state supplied from the liquefied gas tank 55. As long as the vaporizer 57 can vaporize the liquefied gas supplied in liquid state, it may use a known vaporization method such as a hot water method. The heat source supplied to the vaporizer 57 is supplied from inside the liquefied gas fueled ship 1.

The fuel gas supply system 63 is a device that adjusts the flow rate and pressure of the liquefied gas vaporized in the vaporizer 57 to values suitable for driving the internal combustion engine 75 and supplies the gas to the internal combustion engine 75 .
The fuel gas supply system 63 includes at least a compressor 43b as shown in Fig. 3. In Fig. 3, the fuel gas supply system 63 also includes a buffer tank 43a, but the buffer tank 43a may not be included.
3 is a small tank that adjusts the pressure by temporarily storing the vaporized liquefied gas supplied from the vaporizer 57. A known pressure-resistant container may be used as the buffer tank 43a as long as the vaporized liquefied gas can be stored at a desired pressure. The compressor 43b is a device that adjusts the flow rate of the gas sent from the buffer tank 43a and supplies it to the internal combustion engine 75. A known electric or hydraulic compressor may be used as the compressor 43b as long as the gas can be adjusted to a desired flow rate.

The switchboard 45 shown in Fig. 2 is a transformer that transforms the voltage of the power supplied from the generator 77 to a value suitable for driving the electric motor 37 and supplies the transformed voltage to the electric motor 37, and is connected to the generator 77 and the electric motor 37 by power lines to relay the electric power. The switchboard 45 shown in Fig. 2 is fixed to the inner bottom plate 21 of the bottom 5 of the vessel, which is the floor of the propulsion compartment 31. Any known transformer may be used for the switchboard 45 as long as it is not damaged by the electric power supplied from the generator 77 and can transform the supplied electric power to the desired voltage.
The above has described the schematic configuration of the liquefied gas fuelled ship 1 according to the first embodiment.

Next, the structure of the liquefied gas fuelled ship 1 will be described in more detail with reference to Figures 1 to 8.
As shown in Figures 1 and 2, the liquefied gas fuelled ship 1 is equipped with a fuel container 41, a fuel gas supply container 43, and a power generation container 39.

The fuel container 41 is a container equipped with a liquefied gas tank 55 and equipment for vaporizing the liquefied gas. As shown in Figures 2 and 3, the fuel container 41 includes a liquefied gas tank 55, a vaporizer 57, a liquid outlet 41a, liquid piping 41b, a gas outlet 41c, and a fuel container frame 51.

As shown in FIG. 3, the liquefied gas tank 55 is provided with a liquid outlet 41a, which is a connecting pipe that serves as an outlet for sending out liquefied gas in a liquid state. The vaporizer 57 is connected to the liquid outlet 41a of the liquefied gas tank 55 through a liquid piping 41b, and gas in a liquid state is supplied to the vaporizer 57. A gas outlet 41c, which is a gas pipe, is also connected to the vaporizer 57, and the gas vaporized by the vaporizer 57 is sent in a gaseous state from the gas outlet 41c to the onboard piping 91, which is a gas pipe composed of a flexible hose or the like, and is sent to the fuel gas supply container 43. Note that FIG. 3 omits the illustration of the pipeline used to fill the liquefied gas tank 55 with liquefied gas. In addition, if power is required to drive the vaporizer 57, power can be supplied from the distribution board 45 shown in FIG. 2 by connecting the distribution board 45 and the vaporizer 57 with a power line, for example.

The fuel container frame 51 is a container frame on which the liquefied gas tank 55, the vaporizer 57, the liquid outlet 41a, the liquid piping 41b, and the gas outlet 41c are mounted, that is, the outer frame of the container.
2 illustrates a frame-like structure as the fuel container frame 51, in which the portions corresponding to the edges of a rectangular parallelepiped are formed of straight frames and trusses are provided to reinforce the portions corresponding to the side surfaces of the rectangular parallelepiped, similar to the frame of a tank container. A floor may be provided on the portion corresponding to the bottom surface of the rectangular parallelepiped. Also, a container having a floor, side walls, and a top wall, such as a shipping container, may be used as the fuel container frame 51 as it is.

The liquefied gas tank 55, the vaporizer 57, the liquid outlet 41a, the liquid piping 41b, and the gas outlet 41c are mounted on the fuel container frame 51 by being fixed to the fuel container frame 51 or to a floor surface fixed to the fuel container frame 51 by known fixing means such as bolts. The liquefied gas tank 55, the vaporizer 57, the liquid outlet 41a, the liquid piping 41b, and the gas outlet 41c may be provided detachably on the fuel container frame 51.

The external dimensions of the fuel container frame 51 shown in FIG. 2 are such that at least a liquefied gas tank 55 and a vaporizer 57 can be mounted. It is preferable to make the external dimensions the same as those of a standardized container such as an ISO 20-foot or 40-foot container, because this allows the use of standardized container lifting equipment when mounting the frame on the hull 3.

As shown in FIG. 4(a), the fuel container frame 51 has long holes 101 at the four corners of the upper and lower surfaces. The long holes 101 are holes provided to hold the fuel container 41 detachably on the hull 3.

As shown in FIG. 2, the fuel container 41 is removably held by a holding mechanism 59 provided on the hull 3. In FIG. 2, the fuel container 41 is removably held by a holding mechanism 59 provided on the upper surface of an installation stand 60 installed on the exposed deck 9.

The holding mechanism 59 shown in Figure 4 is a mechanism known as a twist lock. In this mechanism, a rotating hook called a twist lock pin 111 is inserted into the long holes 101 provided at the four corners of the underside of the fuel container frame 51 and rotated around the axis in the Z direction to a position that prevents it from coming out of the long holes 101. In this way, the fuel container frame 51 is removably held in the holding mechanism 59.

Specifically, the holding mechanism 59 includes a twist lock pin 111 and a guide block 113. The twist lock pin 111 is an arrow-shaped hook in FIG. 4, and is provided to protrude upward from the upper surface of the installation base 60, which is the installation surface of the fuel container frame 51, so as to be rotatable about an axis 115 that faces the vertical Z direction. The tip of the twist lock pin 111 has an outer shape that corresponds to the inner circumference of the long hole 101. Specifically, the tip of the twist lock pin 111 has a maximum width W in the Y direction shown in FIG. 4(a) that is slightly shorter than the width D1 in the Y direction that is perpendicular to the longitudinal direction of the long hole 101. On the other hand, FIG. 4(b) shows a state in which the twist lock pin 111 is rotated 90° from the state shown in FIG. 4(a), and the maximum length L in the horizontal direction perpendicular to the width direction is longer than the width D1 in the Y direction of the long hole 101 and slightly shorter than the longitudinal length of the long hole 101. Therefore, the twist lock pin 111 has a planar shape corresponding to the elongated hole 101 .
The guide block 113 is a cylindrical member surrounding the shaft 115, and has an outer shape that corresponds to the inner circumference of the elongated hole 101. Specifically, the maximum width W in the Y direction and the maximum length in the longitudinal direction are approximately the same as those of the twist lock pin 111. Furthermore, the height H of the guide block 113 in the Z direction is slightly longer than the thickness T of the elongated hole 101 in the Z direction.

The procedure for removably holding the fuel container frame 51 in the holding mechanism 59 with this structure is as follows. First, as shown in FIG. 4(a), the twist lock pin 111 and the guide block 113 are inserted into the long hole 101 by aligning the longitudinal directions of the planar shapes of the twist lock pin 111, the guide block 113, and the long hole 101. The insertion depth is greater than or equal to the depth at which the twist lock pin 111 does not contact the inner circumference of the long hole 101. Next, in this state, as shown in FIG. 4(b), the twist lock pin 111 is rotated 90° so that the longitudinal direction intersects with the long hole 101. In this state, even if the fuel container frame 51 is moved in the Z direction, the bottom surface of the hook-shaped portion at the tip of the twist lock pin 111 is caught on the upper edge of the long hole 101 of the fuel container frame 51, so that the movement of the fuel container frame 51 in the Z direction is restricted. Furthermore, even if the fuel container frame 51 is moved horizontally, the inner circumference of the long hole 101 abuts against the guide block 113, restricting horizontal movement. If you wish to remove the fuel container frame 51 from the state shown in FIG. 4(b), simply rotate the twist lock pin 111 90° so that the longitudinal direction is aligned with the long hole 101.

In this way, by configuring the holding mechanism 59 with the twist lock pin 111, the fuel container 41 can be removably held by a twist lock, which is a general-purpose item used as a holding device for existing transport containers.
If the holding strength of the holding mechanism 59 alone is insufficient, other holding means such as lashings may be used in combination.

Furthermore, the holding mechanism 59 does not have to be a structure using the twist lock pin 111, but may be a cell guide 121, which is a frame that is provided on the installation surface of the fuel container 41 and surrounds the side surface of the fuel container frame 51, as shown in FIG.
The cell guide 121 shown in Figure 5 is an example of a structure installed on the exposed deck 9 as the installation surface for the fuel container 41, and is equipped with a lashing bridge 123 and a lashing bar 125.

The lashing bridge 123 is a bridge-shaped structure that is part of the frame that constitutes the cell guide 121 and also serves as a work platform when holding the fuel container 41 on the hull 3. The lashing bridge 123 shown in FIG. 5 has its longitudinal direction facing the Y direction, which is the width direction of the hull 3, and multiple lashing bridges 123 are provided in the X direction at intervals corresponding to the longitudinal length of the fuel container 41.

The lashing bars 125 are part of the frame that constitutes the cell guide 121, and are multiple plate-shaped members that protrude in the X direction from the surface of the lashing bridge 123 facing the X direction and are parallel to the X-Z plane. The installation intervals of the multiple lashing bars 125 in the Y direction correspond to the width of the container in the Y direction.

In this structure, the fuel container 41 is mounted on the installation surface of the exposed deck 9, which is surrounded by two lashing bridges 123 and four lashing bars 125, with the longitudinal direction of the fuel container 41 facing the X direction. As a result, the fuel container 41 is surrounded and held by the cell guides 121, and movement in the X and Y directions is restricted. If necessary, movement in the Z direction can also be restricted by fastening the fuel container 41 to the exposed deck 9 or the lashing bridges 123 with lashings or the like. The installation position of the cell guides 121 is not limited to the exposed deck 9, and can be provided at the installation position of the fuel container 41.

In this way, the cell guide 121 may be used as the holding mechanism 59. In this structure, the cell guide 121, which is a general-purpose equipment used to hold containers on container ships, can be used as a means to hold the fuel container 41.

In this way, by mounting the liquefied gas tank 55 and vaporizer 57 on the fuel container frame 51 to form a fuel container 41 that supplies liquefied gas in a gaseous state to the ship, the onboard piping 91 becomes a gas pipe. Therefore, there is no need to flow gas in a liquid state through the onboard piping 91, and the leakage prevention structure for liquefied gas is not as complicated as that for piping for liquefied gas, resulting in excellent workability.

In addition, by removably holding the fuel container 41 in the holding mechanism 59, the fuel container 41 can be easily replaced when the liquefied gas tank 55 is empty or when changing the type of fuel used, further improving workability. Furthermore, since the onboard piping 91 that is removed from the fuel container 41 when attaching or detaching the fuel container 41 is a gas pipe, measures to prevent leakage of low-temperature liquid are not required when attaching or detaching the fuel container 41, compared to when liquid gas is flowed through the onboard piping 91, which is further advantageous in terms of workability.

In addition, since the fuel container 41 is removably held by the holding mechanism 59, when the liquefied gas tank 55 becomes empty, the fuel container 41 can be removed from the hull 3 and transported to land, where it can be refilled with liquefied gas. Therefore, there is no need to perform the refilling work on board the ship when refilling the liquefied gas tank 55 with liquefied gas, which is an added advantage in terms of workability.

The liquefied gas tank 55 and the vaporizer 57 do not necessarily have to be mounted together in one fuel container frame 51. As shown in FIG. 6, the liquefied gas tank 55 and the vaporizer 57 may be arranged in two container frames 42a and 42b, respectively, and the container frames 42a and 42b may be connected in the vertical direction by engaging a connecting jig such as a stacking cone with the long hole 101. In this configuration, the dimensions of the liquefied gas tank 55 and the vaporizer 57 can be made larger than when the liquefied gas tank 55 and the vaporizer 57 are mounted together in one fuel container frame 51.

The fuel gas supply container 43 shown in FIG. 2 is a container equipped with a fuel gas supply system 63, and in FIG. 2, is mounted on the second deck 23 of the fuel gas supply section 27. As shown in FIG. 2, the fuel gas supply container 43 is equipped with a fuel gas supply system 63 and a fuel gas supply container frame 61.

As shown in FIG. 3, the fuel gas supply container 43 includes a buffer tank 43a, a compressor 43b, and a tank side connection portion 43c.

As shown in FIG. 3, the buffer tank 43a is connected to the carburetor 57 of the fuel container 41 via onboard piping 91. The compressor 43b is connected to the internal combustion engine 75 via onboard piping 93 shown in FIG. 2. The onboard piping 93 is a gas pipe composed of a flexible hose or the like.

The tank side connection 43c is a connection that connects the vaporizer 57 and the buffer tank 43a, and specifically, is a connection that connects the gas outlet 41c of the fuel container 41 and the buffer tank 43a via the onboard piping 91. Since the gas supplied from the gas outlet 41c is a gas, the onboard piping 91 is a gas pipe. As shown in FIG. 3, the tank side connection 43c is provided in a number corresponding to the number of fuel containers 41 that can be mounted on the hull 3, and is combined into one pipe at the end on the buffer tank 43a side and connected to the buffer tank 43a. FIG. 3 illustrates three tank side connection parts 43c, and illustrates a case where the fuel container 41 is connected to two of them.

The onboard piping 91 is provided with automatic stop valves at both ends, which are connected to the gas outlet 41c and the tank side connection 43c, and are closed when the gas outlet 41c and the tank side connection 43c are not connected, and are opened when the gas outlet 41c and the tank side connection 43c are connected. A branch pipe (not shown) is provided between both ends of the onboard piping 91, and an inert gas such as nitrogen gas can be filled from the branch pipe. This is because, when connecting the vaporizer 57 and the buffer tank 43a, it is necessary to fill the onboard piping 91 with an inert gas in advance to prevent air from entering these devices. It is preferable that the connection parts at both ends of the onboard piping 93 are also provided with automatic stop valves, and it is preferable that the inert gas can be filled from a branch pipe (not shown) provided between the two ends.

The fuel gas supply container frame 61 shown in FIG. 2 is a container frame on which the fuel gas supply system 63 is mounted, that is, the outer frame of the container. The structure of the fuel gas supply container frame 61 is a frame-like structure in which the parts corresponding to the edges of a rectangular parallelepiped are composed of straight frames, similar to the fuel container frame 51, and trusses are provided to the parts corresponding to the side surfaces of the rectangular parallelepiped for reinforcement. A transport container may be used as the fuel gas supply container frame 61 as is. The structure in which the fuel gas supply container frame 61 is detachably held by the holding mechanism 59 is also similar to that of the fuel container frame 51, and is a structure in which a twist lock pin 111 provided on the installation surface is inserted into a long hole 101 and rotated as shown in FIG. 4. The frame may also be held using a cell guide 121 shown in FIG. 5.

The fuel gas supply system 63 is fixed to the fuel gas supply container frame 61 or to a floor surface fixed to the fuel gas supply container frame 61 by known fixing means such as bolts, and is thereby mounted on the fuel gas supply container frame 61. The fuel gas supply system 63 may be detachably provided on the fuel gas supply container frame 61.

The external dimensions of the fuel gas supply container frame 61 are at least large enough to accommodate the fuel gas supply system 63. It is preferable to have the same dimensions as a standardized container, since this allows the use of standardized container lifting equipment when mounting the frame on the hull 3.

In this way, the liquefied gas fuelled ship 1 is configured such that the fuel gas supply system 63 is mounted on a single fuel gas supply container frame 61 to form the fuel gas supply container 43, and is detachably held by the holding mechanism 59.
Since the fuel gas supply system 63 has a different structure depending on the type of fuel, when changing the fuel used for combustion of the internal combustion engine 75, it is necessary to remove the existing fuel gas supply container 43. In this case, since the fuel gas supply container 43 is detachable from the hull 3, it is sufficient to replace it with a fuel gas supply container 43 equipped with a fuel gas supply system 63 having a structure corresponding to the changed fuel, and there is no need to modify the hull 3. In addition, when performing maintenance such as inspection or repair of the fuel gas supply system 63, the fuel gas supply container 43 can be removed from the hull 3 and maintenance can be performed at a maintenance factory on land. Therefore, compared to when maintenance is performed on board the ship, it is easier to secure personnel and space for maintenance, which is very advantageous in terms of workability.
Furthermore, in this configuration, since the liquefied gas is supplied in a gaseous state from the fuel container 41, the onboard piping 91, 93 that is attached and detached when the fuel gas supply container 43 is attached and detached is a gas pipe. Therefore, compared to a configuration in which fuel is supplied in a liquid state to the onboard piping 91, 93, measures against leakage of low-temperature liquid and the like are not required when the fuel gas supply container 43 is attached and detached, which is extremely advantageous in terms of workability.

The power generation container 39 shown in Fig. 2 is a container in which an internal combustion engine 75 and a generator 77 serving as a power supply unit 78 are mounted, and in Fig. 2, it is mounted on the third deck 25 of the power generation section 29. The power generation container 39 includes the internal combustion engine 75, the generator 77, and a power generation container frame 73.
The internal combustion engine 75 is connected to the fuel container 41 via an onboard piping 93 which is a gas pipe, a fuel gas supply system 63, and an onboard piping 91 which is a gas pipe, and the liquefied gas stored in the liquefied gas tank 55 is supplied in a gaseous state from the fuel gas supply system 63.

The power generation container frame 73 is the frame of the container on which the internal combustion engine 75 and the generator 77 are mounted, that is, the outer frame of the container. The power generation container frame 73 has a structure similar to that of the fuel container frame 51, in which the parts corresponding to the edges of a rectangular parallelepiped are made of straight frames, and a frame-like structure is exemplified in which trusses are provided to reinforce the parts corresponding to the side surfaces of the rectangular parallelepiped. A transport container may be used as the power generation container frame 73 as is. The structure in which the power generation container frame 73 is detachably held by the holding mechanism 59 is also similar to that of the fuel container frame 51, and the twist lock pin 111 provided on the third deck 25 is inserted into the long hole 101 to rotate the frame. The power generation container frame 73 may also be held using the cell guide 121 shown in FIG. 5.

The internal combustion engine 75 and the generator 77 are fixed to the power generation container frame 73 or to a floor surface fixed to the power generation container frame 73 by known fixing means such as bolts, and are thus mounted on the power generation container frame 73. The internal combustion engine 75 and the generator 77 may be detachably mounted on the power generation container frame 73.

The external dimensions of the power generation container frame 73 are such that at least an internal combustion engine 75 and a generator 77 can be mounted on it. It is preferable to have the same dimensions as a standardized container, since this allows the use of standardized container lifting equipment when mounting it on the hull 3.

In this way, the liquefied gas fueled ship 1 is configured such that the internal combustion engine 75 and the generator 77 are mounted together on one power generation container frame 73 to form a power generation container 39 that generates power and are detachably held by the holding mechanism 59. In this configuration, when changing the fuel used for combustion in the internal combustion engine 75, the existing power generation container 39 can be removed and replaced with a power generation container 39 equipped with an internal combustion engine 75 having a structure corresponding to the changed fuel, so there is no need to modify the hull 3. In addition, even when performing maintenance on the internal combustion engine 75 and the generator 77, the power generation container 39 can be removed from the hull 3 and the maintenance can be performed at a maintenance factory on land. Therefore, compared to when maintenance is performed on board the ship, it is easier to secure personnel and space for maintenance, which is very advantageous in terms of workability.
Furthermore, in this configuration, since the liquefied gas is supplied in a gaseous state from the fuel container 41, the onboard piping 91, 93 that is also attached and detached when attaching and detaching the power generation container 39 are all gas pipes. Therefore, compared to a configuration in which fuel is supplied in a liquid state to the onboard piping 91, 93, measures against leakage of low-temperature liquid when attaching and detaching the power generation container 39 are not required, which is extremely advantageous in terms of workability.

In this manner, in the liquefied gas fuelled ship 1, the liquefied gas tank 55 and the vaporizer 57 are mounted on the fuel container frame 51 to form the fuel container 41, and the fuel gas supply system 63 is mounted on the fuel gas supply container frame 61 to form the fuel gas supply container 43. In addition, the power supply device 78 is mounted on the power generation container frame 73 to form the power generation container 39.
Furthermore, in the liquefied gas fuelled ship 1, the onboard piping 91 connecting the fuel container 41 and the fuel gas supply container 43, and the onboard piping 93 connecting the fuel gas supply container 43 and the power generation container 39 are gas pipes.

In this configuration, since the onboard piping 91, 93 is a gas pipe, there is no need to flow liquid gas through the onboard piping 91, 93, and work such as pre-cooling is not required. In addition, the gas leakage prevention structure of the onboard piping 91, 93 is not as complicated as that of piping for liquefied gas, resulting in excellent workability.
Furthermore, by detachably holding the fuel container 41, the fuel gas supply container 43, and the power generation container 39 in the holding mechanism 59, these containers can be easily removed and replaced, further improving workability.

In addition, by detachably holding the fuel container 41, the fuel gas supply container 43, and the power generation container 39 in the holding mechanism 59, it is also possible to lease these containers individually, thereby reducing the investment risk in the construction of the liquefied gas fueled ship 1. In particular, a liquefied gas fueled ship has a wide variety of liquefied gases expected as fuel, and the future prospects of each liquefied gas are unclear. Therefore, if a ship is constructed with a propulsion mechanism for a specific liquefied gas fixed to the hull 3, when the corresponding liquefied gas loses its future prospects and is no longer used, the ship itself may become unusable if the propulsion mechanism cannot be removed from the hull 3. Therefore, compared to the construction of ships that run on existing fuels such as heavy oil, the construction of liquefied gas fueled ships tends to be disliked as it involves a high investment risk. On the other hand, the liquefied gas fueled ship 1 of the first embodiment can continue to operate even if the liquefied gas corresponding to the installed fuel container 41, power generation container 39, and fuel gas supply container 43 is no longer used, by leasing a container for a practical liquefied gas and replacing the existing container. This reduces the investment risk in building liquefied gas fuelled ship 1.

The installation positions of the fuel container 41, the fuel gas supply container 43, and the power generation container 39 can be set appropriately as long as they do not interfere with other equipment installed on the liquefied gas fueled ship 1, the onboard piping 91, 93 can be routed, and the holding mechanism 59 can hold them on the hull 3. However, as shown in FIG. 1, it is preferable to install the fuel container 41 on the exposed deck 9 rather than inside the ship. The reason is as follows. The fuel container 41 needs to be replaced when the liquefied gas in the liquefied gas tank 55 is consumed and emptied during the voyage of the liquefied gas fueled ship 1, so it is attached and detached more frequently than the power generation container 39 and the fuel gas supply container 43. Therefore, it is more workable to install the fuel container 41 on the exposed deck 9, which is easier to access from land than inside the ship. The fuel container 41 in FIG. 1 is installed at the stern end of the exposed deck 9.

The fuel gas supply container 43 and the power generation container 39 are only detached during maintenance or when changing the fuel used, so they do not have to be installed on the exposed deck 9. However, if the liquefied gas fueled ship 1 is a cargo ship, it is preferable to place them in a section where no cargo is carried. This is because if the power generation container 39 and the fuel gas supply container 43 are installed in a section where cargo is carried, such as the cargo section 13 shown in Figure 1, the cargo load capacity will be reduced by the volume of these containers.

Specifically, it is preferable to provide the fuel gas supply container 43 and the power generation container 39 in the engine space 11 shown in Fig. 1. The reasons are as follows. First, the engine space 11 shown in Fig. 1 is a space below the deckhouse 33, and therefore a transport container lifted from land by a crane or the like cannot be directly loaded from above into the engine space 11, and therefore the engine space 11 is not used as a space for loading cargo. Second, in Fig. 1, the switchboard 45 and the electric motor 37 are arranged in the engine space 11, and the fuel container 41 is loaded on the exposed deck 9 above the engine space 11. For this reason, the power lines and the onboard piping 91, 93 can be made shorter by loading the power generation container 39 and the fuel gas supply container 43 in the engine space 11 than in the cargo space 13 or the bow space 15.
Therefore, as shown in Figure 1, it is preferable that the fuel gas supply container 43 and the power generation container 39 are arranged in the fuel gas supply compartment 27 and the power generation compartment 29, which are onboard compartments below the deckhouse 33 and above the electric motor 37 in the engine compartment 11.

However, when the fuel gas supply container 43 and the power generation container 39 are installed below the deckhouse 33, these containers cannot be directly loaded from above into the engine room 11 after being lifted from land by a crane or the like. Therefore, as shown in FIG. 2, the engine room transverse bulkhead 17 is formed with an openable transverse bulkhead opening 81 that serves as a route for installing the power generation container 39 and the fuel gas supply container 43 in the hull 3. When there is no need to transport the fuel gas supply container 43 and the power generation container 39 between the outside and inside of the ship, the transverse bulkhead opening 81 is closed with a watertight door (not shown). When there is a need to transport the fuel gas supply container 43 and the power generation container 39 between the outside and inside of the ship, the watertight door opens. The dimensions of the transverse bulkhead opening 81 are large enough to allow at least the power generation container 39 and the fuel gas supply container 43 to pass through.

In this configuration, the fuel gas supply container 43 and the power generation container 39 are loaded from the cargo space 13 through the transverse bulkhead opening 81 into the engine space 11, which is an inboard space below the deckhouse 33.
No cargo is carried in the ship's compartment below the deckhouse 33 because containers cannot be directly lowered from above using a crane or the like. Therefore, by loading the fuel gas supply container 43 and the power generation container 39 in the machinery compartment 11 below the deckhouse 33, it is no longer necessary to load the power generation container 39 and the fuel gas supply container 43 in the cargo compartment 13, and the volume of the cargo compartment 13 can be increased.

The fuel gas supply container 43 and the power generation container 39 may be located on different decks within the ship, as shown in FIG. 2. For example, in FIG. 2, the fuel gas supply container 43 is located on the second deck 23 in the fuel gas supply compartment 27 of the engine compartment 11. The power generation container 39 is located on the third deck 25 in the power generation compartment 29 of the engine compartment 11, and is located below the fuel gas supply container 43.

In this way, by arranging the fuel gas supply container 43 and the power generation container 39 on decks located at different height positions within the engine compartment 11, the length of the engine compartment 11 in the ship's longitudinal direction can be shortened and the volume of the cargo compartment 13 can be increased.

Either the fuel gas supply container 43 or the power generation container 39 may be placed on top. However, when the fuel container 41 is provided on the exposed deck 9 and the switchboard 45 and the electric motor 37 are provided on the inner bottom plate 21 as shown in Figure 2, it is preferable to place the fuel gas supply container 43 above the power generation container 39. The reason is as follows.
Placing the fuel gas supply container 43 above the power generation container 39 brings the fuel gas supply container 43 and the fuel container 41 closer together. This shortens the length of the onboard piping 91, which is the gas pipe for connection, and also shortens the leakage prevention structure, improving workability. Also, placing the power generation container 39 below the fuel gas supply container 43 brings the power distribution board 45 closer together, and the wiring of the power lines is shorter, which shortens the leakage prevention structure and improves workability.

When the fuel gas supply container 43 is placed on the second deck 23 and the power generation container 39 is provided on the third deck 25, the transverse bulkhead opening 81 may be provided in two places, one in contact with the fuel gas supply compartment 27 of the engine room transverse bulkhead 17 and the other in contact with the power generation compartment 29. In this configuration, the fuel gas supply container 43 is brought into the fuel gas supply compartment 27 through the transverse bulkhead opening 81 provided in the part in contact with the fuel gas supply compartment 27. The power generation container 39 is brought into the power generation compartment 29 through the transverse bulkhead opening 81 provided in the part in contact with the power generation compartment 29. However, if providing the transverse bulkhead openings 81 in two places weakens the strength and watertight structure of the engine room transverse bulkhead 17, it is preferable to provide only one transverse bulkhead opening 81 in the part in contact with the fuel gas supply compartment 27 of the engine room transverse bulkhead 17 as shown in FIG. 2.

When the power generation container 39 is transported from outside the ship to the third deck 25 for installation in this structure, it is necessary to first transport the power generation container 39 from the cargo section 13 through the transverse bulkhead opening 81 into the fuel gas supply section 27, and then transport it from the fuel gas supply section 27 to the power generation section 29. Therefore, as shown in FIG. 2, a deck opening 83 is provided on the second deck 23, which is an opening that serves as a route for installing the power generation container 39. The deck opening 83 is an opening that connects the fuel gas supply section 27 and the power generation section 29. The dimensions of the deck opening 83 are such that at least the power generation container 39 can pass through. As a means for transporting the power generation container 39 from the fuel gas supply section 27 to the power generation section 29, an overhead crane 87 installed on the underside of the exposed deck 9 in the fuel gas supply section 27, as shown in FIG. 2, can be used. Specifically, the power generation container 39 that has been brought into the fuel gas supply area 27 is lifted by an overhead crane 87, carried from the fuel gas supply area 27 through the deck opening 83 into the power generation area 29, and then installed on the third deck 25.

In this configuration, the power generation container 39 is loaded into the power generation compartment 29 via the cargo compartment 13, the transverse bulkhead opening 81, the fuel gas supply compartment 27, and the deck opening 83, and the reverse route is followed when removing it. Therefore, even if multiple compartments are provided vertically below the deckhouse 33, the power generation container 39 can be transported from outside the ship to the compartment below the deckhouse 33, and the power generation container 39 can be transported outside the ship from the compartment below the deckhouse 33.

When providing a deck opening 83, the transverse bulkhead opening 81 may be provided only in the portion of the engine room transverse bulkhead 17 that contacts the power generation compartment 29. However, in the following explanation, the first embodiment will be explained using an example in which the transverse bulkhead opening 81 is provided only in the portion of the engine room transverse bulkhead 17 that contacts the fuel gas supply compartment 27.

It is preferable that the deck opening 83 has a structure that allows it to be closed when the power generation container 39 is not being loaded or removed. If the deck opening 83 does not have a structure that allows it to be closed, the deck opening 83 will become a dead space in which other onboard equipment cannot be installed when the power generation container 39 is not being loaded or removed. However, the structure that closes the deck opening 83 does not need to be watertight, and it does not need to be completely closed with a watertight door or the like. The watertight structure of the machinery space 11 in which the deck opening 83 is installed is ensured by the engine room transverse bulkhead 17, the ship bottom 5, the side walls 7, and the exposed deck 9 shown in Figure 1.

Figure 2 illustrates a structure for blocking the deck opening 83, in which multiple rails 85 are detachably held on the second deck 23 across the deck opening 83. The rails 85 are long plates that span the deck opening 83 in the X or Y direction, and Figure 2 illustrates a long plate that spans the deck opening 83 in the X direction. The installation intervals of the multiple rails 85 are sufficient to allow the fuel gas supply container 43 to be loaded. For example, when multiple rails 85 span the deck opening 83 in the X direction as shown in Figure 2, the installation intervals of the multiple rails 85 in the Y direction may be shorter than the width of the fuel gas supply container 43 in the Y direction. In this case, if a holding mechanism 59 is provided on the rails 85, the fuel gas supply container 43 can be detachably held on the rails 85.

In this configuration, when the power generation container 39 is loaded onto the third deck 25 of the power generation section 29, the rail 85 is first removed from the deck opening 83 to ensure an aisle for the power generation container 39. Next, the power generation container 39 is transported from the cargo section 13 into the fuel gas supply section 27 through the transverse bulkhead opening 81, and then into the power generation section 29 through the deck opening 83 and loaded onto the third deck 25. The rail 85 is then placed across the deck opening 83 and secured with a fastening means such as a bolt, and the fuel gas supply container 43 is transported from the cargo section 13 into the fuel gas supply section 27 through the transverse bulkhead opening 81 and installed on the rail 85. In this configuration, the deck opening 83 is easier to open and close than when the deck opening 83 is completely blocked by a watertight door or the like, and the fuel gas supply container 43 can be installed above the deck opening 83.

The rail 85 shown in FIG. 2 has its length facing the X direction, which is the ship's length direction, but in this case, the rail 85 may be configured to be slidable in the X direction like a slide rail. In this configuration, when closing the deck opening 83, the rail 85 is slid in the X direction so as to straddle the deck opening 83. Also, when loading/unloading the power generation container 39, the rail 85 is slid in the X direction away from the deck opening 83.

The range in which the rail 85 can slide is at least the range in which the power generation container 39 can be loaded/unloaded from the deck opening 83 and the deck opening 83 can be spanned. Therefore, the rail 85 may be configured to be slid from the transverse bulkhead opening 81 to a position where it protrudes into the cargo compartment 13 by aligning the Y-direction position and Z-direction position at which the rail 85 is installed with the transverse bulkhead opening 81 (see FIG. 9(a)).

In this way, by sliding the rail 85 in a direction protruding from the transverse bulkhead opening 81 into the cargo compartment 13, the power generation container 39 can be brought into the ship as follows. First, the power generation container 39 is lowered from above the cargo compartment 13 while suspended by a quay crane 200 or the like, and is loaded onto the rail 85 protruding from the transverse bulkhead opening 81 into the cargo compartment 13 (see FIG. 9(b)). Next, the power generation container 39 can be brought into the engine compartment 11 by pulling the rail 85 into the engine compartment 11. After being brought into the fuel gas supply compartment 27 of the engine compartment 11, the power generation container 39 can be loaded into the power generation compartment 29 by the overhead crane 87 (see FIG. 10(b)). The fuel gas supply container 43 can also be loaded into the fuel gas supply compartment 27 by loading it onto the rail 85 protruding into the cargo compartment 13 and sliding the rail 85 (see FIG. 12(a)).

As shown in FIG. 7, the power generation container 39 and the fuel gas supply container 43 may be provided on the same deck within the ship. In FIG. 7, the power generation container 39 and the fuel gas supply container 43 are provided on the second deck 23 of the engine room 11. This configuration does not require a deck opening 83, which is advantageous in terms of watertightness of the room.

The liquefied gas-fueled ship 1 shown in Fig. 2 is a ship that uses liquefied gas as fuel, but is also an electric propulsion ship that drives a propeller 35 with an electric motor 37. Therefore, an internal combustion engine 75 is driven by liquefied gas to generate electricity in a generator 77, and the generated electricity is used to drive the electric motor 37.
When the propeller 35 is driven by the electric motor 37 in this manner, the liquefied gas fueled ship 1 may further include a storage battery 137 as shown in FIG. 8 as a means for supplying power to the electric motor 37.

Specifically, in the modified liquefied gas fueled ship 1 shown in FIG. 8, an installation stand 60 installed on the exposed deck 9 is provided as a battery container 131. The battery container 131 is equipped with a storage battery 137 and a storage container frame 135.

The storage battery 137 is a battery that supplies power to the electric motor 37, and is configured to be electrically connected to the switchboard 45 to supply power. The storage battery 137 is a secondary battery such as a lithium-ion battery, and is charged by the power generated by the generator 77 being supplied via the switchboard 45.

The electricity storage container frame 135 is a container frame on which the storage battery 137 is mounted, that is, the outer frame of the container. The structure of the electricity storage container frame 135 is a frame-like structure in which the parts corresponding to the edges of a rectangular parallelepiped are formed of straight frames, and trusses are provided to reinforce the parts corresponding to the side surfaces of the rectangular parallelepiped, as in the fuel container frame 51. A transport container may be used as the electricity storage container frame 135 as is. The structure in which the electricity storage container frame 135 is detachably held by the holding mechanism 59 is also the same as that of the fuel container frame 51, and an example of a structure in which a twist lock pin 111 provided on the exposed deck 9 is inserted into a long hole 101 and rotated. When stacking multiple containers vertically as shown in FIG. 8, the second and subsequent containers may be connected to the lower container by a stacking cone. In addition, multiple containers can be stacked vertically by making the height of the frame of the cell guide 121 shown in FIG. 5 equal to or greater than two containers. In addition, if the cell guide 121 has a structure in which containers can be loaded in the Y direction, that is, in parallel, multiple containers can also be stacked horizontally.

In this manner, the liquefied gas fueled ship 1 may include the battery container 131. In this configuration, the electric motor 37 can be driven by receiving electric power from the storage battery 137 in the battery container 131. Therefore, the liquefied gas fueled ship 1 can self-propel even when the generator 77 and the internal combustion engine 75 are not operating. Also, in this configuration, the electric power generated by the generator 77 can be charged to the storage battery 137 in the battery container 131 via the switchboard 45, so that surplus electric power generated by the generator 77 can be used as electric power to drive the electric motor 37. Note that the electric power charged in the storage battery 137 may be used to drive onboard equipment other than the propulsion mechanism, for example, the ceiling crane 87.
The above is a more detailed description of the structure of the liquefied gas fuelled ship 1.

Next, the method of mounting the fuel container 41, fuel gas supply container 43, and power generation container 39 on the hull 3 of the liquefied gas fueled ship 1 according to the first embodiment will be briefly explained with reference to Figures 9 to 12.

First, as shown in FIG. 9(a), a crane installed on the quay of the port, such as a quay crane 200, lifts the fuel container 41 from the quay and moves it in the Z1 direction in FIG. 9(a) to land it on the installation stand 60, and the holding mechanism 59 holds the fuel container 41.

Next, the watertight door (not shown) of the transverse bulkhead opening 81 is opened, and the rails 85 are slid in the X1 direction as shown in Figure 9(a) to protrude from the transverse bulkhead opening 81 into the cargo section 13. Next, the power-generation container 39 is hoisted from the quay by the quay crane 200. Furthermore, the power-generation container 39 is moved in the Z2 direction through a hatch (not shown) or the like above the cargo section 13 and carried into the cargo section 13, and then the power-generation container 39 is loaded onto the rails 85 protruding into the cargo section 13 as shown in Figure 9(b).
Next, as shown in FIG. 9B, the rail 85 is moved in the X2 direction to pull the power generation container 39 into the fuel gas supply section 27 through the horizontal bulkhead opening 81.

If the rail 85 is not designed to slide, the power generation container 39 is pulled into the fuel gas supply section 27 as follows. First, the power generation container 39 is lifted by the quay crane 200 and carried into the cargo section 13, and its position in the Z and Y directions is aligned with the transverse bulkhead opening 81, and a rope (not shown) is tied to the power generation container 39. Next, the rope is pulled in the direction of X2 in Figure 9(b) to pull the power generation container 39 from the cargo section 13 into the fuel gas supply section 27 through the transverse bulkhead opening 81.

When the power-generation container 39 is pulled into the fuel gas supply section 27, the hoisting gear of the quay crane 200 is removed from the power-generation container 39, and the power-generation container 39 is hoisted in the Z3 direction by the ceiling crane 87 as shown in Fig. 10(a). At this time, the rail 85 is removed or moved in the X2 direction in Fig. 10(a) so that it does not overlap with the deck opening 83 on the plane.
Next, the planar position of the power-generation container 39 is aligned with the planar position of the deck opening 83, and the hoisting tool of the overhead crane 87 is moved in the Z4 direction in Figure 10(b) to carry the power-generation container 39 into the power-generation section 29 through the deck opening 83. Furthermore, as shown in Figure 11(a), the power-generation container 39 is grounded on the third deck 25 and held by the holding mechanism 59. After that, the hoisting tool of the overhead crane 87 is removed from the power-generation container 39.

Next, as shown in Figure 11(b), the rails 85 are slid in the X1 direction so as to protrude again from the transverse bulkhead opening 81 into the cargo section 13. Next, the fuel gas supply container 43 is hoisted from the quay by the quay crane 200. Furthermore, the fuel gas supply container 43 is moved in the Z2 direction in Figure 11(b) through a hatch or the like (not shown) above the cargo section 13 and carried into the cargo section 13, and the fuel gas supply container 43 is loaded onto the rails 85 protruding into the cargo section 13 as shown in Figure 12(a).
Next, as shown in Figure 12(a), the rail 85 is moved in the X2 direction to pull the fuel gas supply container 43 into the fuel gas supply compartment 27 through the transverse bulkhead opening 81, and as shown in Figure 12(b), the rail 85 is fixed in a position spanning the deck opening 83. Thereafter, the fuel gas supply container 43 is held on the rail 85 by the holding mechanism 59. Furthermore, a watertight door (not shown) of the transverse bulkhead opening 81 is closed. After closing the watertight door, the onboard piping 91, 93 and the power lines are connected, completing the loading of the fuel container 41, the fuel gas supply container 43, and the power generation container 39.

If the rails 85 are not structured to slide, the fuel gas supply container 43 is pulled into the fuel gas supply section 27 as follows: First, the fuel gas supply container 43 is hoisted by the quay crane 200 and carried into the cargo section 13, its position in the Y and Z directions is aligned with the transverse bulkhead opening 81, and a rope (not shown) is tied to the fuel gas supply container 43. Next, the rope is pulled in the X2 direction in Figure 12(a) to pull the fuel gas supply container 43 from the cargo section 13 into the fuel gas supply section 27 through the transverse bulkhead opening 81.
The above has described the method of loading the fuel container 41, the fuel gas supply container 43, and the power generation container 39 onto the hull 3 of the liquefied gas fuelled ship 1 according to the first embodiment.

As described above, in the liquefied gas fuelled ship 1 of the first embodiment, the liquefied gas tank 55, the vaporizer 57, the power supply device 78, and the fuel gas supply system 63 are each mounted on a container frame and are detachably arranged in the hull 3. Furthermore, these containers are connected by onboard piping 91, 93 which are gas pipes.
Therefore, there is no need to flow gas in a liquid state through the onboard piping 91, 93, and the gas leakage prevention structure of the onboard piping 91, 93 is not as complicated as that of piping for liquefied gas, resulting in excellent workability. Furthermore, when it is desired to change the fuel to be used, it is sufficient to replace the container in which the liquefied gas tank 55, generator 77, internal combustion engine 75, and fuel gas supply system 63 corresponding to the type of fuel are mounted, and the onboard piping 91, 93 that is detached from the container at this time is a gas pipe. Therefore, workability is further improved.
Therefore, the liquefied gas fuelled ship 1 of the first embodiment has excellent workability and maintainability with less expensive equipment than conventional ones, does not unnecessarily increase the burden on the crew, and does not require new construction or large-scale modifications when changing fuel.

Next, the second embodiment will be described with reference to Figures 13 to 17. In the second embodiment, instead of the transverse bulkhead opening 81, a hatch 141 is provided on the exposed deck 9 above the machinery space 11 as a route for carrying the power generation container 39 and fuel gas supply container 43 from outside the ship into the ship in the first embodiment. In the second embodiment, elements that perform the same functions as those in the first embodiment are given the same numbers, and mainly the parts that differ from the first embodiment will be described.

First, the structure of the liquefied gas fuelled ship 1 according to the second embodiment will be described with reference to FIG. 13 .
In the liquefied gas fuelled ship 1a according to the second embodiment shown in Fig. 13, similarly to the liquefied gas fuelled ship 1 according to the first embodiment, the hull 3 has an engine compartment 11 and a cargo compartment 13 arranged in that order from the stern side to the bow side, and is divided by a transverse bulkhead, which is an engine room transverse bulkhead 17. In addition, a deckhouse 33 is provided on the exposed deck 9 above the engine compartment 11.
The machinery compartment 11 is divided into three compartments on the second deck 23 and the third deck 25, in that order, a fuel gas supply compartment 27, a power generation compartment 29, and a propulsion compartment 31. The power generation container 39 and the fuel gas supply container 43 are respectively disposed in the power generation compartment 29 and the fuel gas supply compartment 27, which are compartments below the deckhouse 33 and above the electric motor 37 in the machinery compartment 11. The electric motor 37 and the switchboard 45 are fixed to the inner bottom plating 21 of the ship bottom 5, which is the floor of the propulsion compartment 31. A deck opening 83 is provided on the second deck 23, which is an opening that serves as a path when the power generation container 39 is installed on the third deck 25.

On the other hand, in the liquefied gas fueled ship 1a according to the second embodiment, the transverse bulkhead opening 81 is not provided in the engine room transverse bulkhead 17, and a hatch 141 and a hatch cover 143 are provided instead of the transverse bulkhead opening 81.

The hatch 141 is an opening which serves as a passage when the power generation container 39 and the fuel gas supply container 43 are installed in the machinery space 11, and is formed above the machinery space 11 on the exposed deck 9 in an area where the deckhouse 33 is not provided. The hatch 141 is formed on the exposed deck 9 at the stern end, which is closer to the stern than the deckhouse 33 in the longitudinal direction in Figure 13, and connects the outside of the hull 3 with the fuel gas supply space 27 of the machinery space 11.
The hatch 141 has a shape and dimensions that allow the power generation container 39 and the fuel gas supply container 43 to pass through. The specific shape is similar to the planar shapes of the power generation container 39 and the fuel gas supply container 43, and the dimensions are larger than the planar dimensions of the power generation container 39 and the fuel gas supply container 43.
By providing the hatch 141, the power generation container 39 and the fuel gas supply container 43 can be carried into the engine compartment 11 from outside the ship through the hatch 141 (see Figures 14(a) and 16(a)).

The hatch cover 143 is a watertight door that covers the hatch 141 in an openable and closable manner, and is provided above the hatch 141. The hatch cover 143 is a watertight door that has a watertight structure that prevents water that is splashed against the exposed deck 9 due to waves or rain from entering the machinery compartment 11 through the hatch 141 when the hatch cover 143 covers the hatch 141. The opening and closing mechanism of the hatch cover 143 may be a known mechanism such as a horizontally sliding mechanism or a mechanism that rotates around a hinge.
By providing the hatch cover 143, even if the hatch 141 is provided, water that is splashed against the exposed deck 9 due to waves or rainfall can be prevented from entering the engine compartment 11 through the hatch 141.

It is preferable that the hatch cover 143 has a structure in which the fuel container 41 can be placed when it is closed. This is because placing the fuel container 41 on the hatch cover 143 prevents the space above the hatch 141 from becoming a dead space. Specifically, as shown in Fig. 13, a holding mechanism 59 may be provided on the upper surface of the hatch cover 143 when it is closed to hold the fuel container 41. In Fig. 13, a holding mechanism 59 provided on the hatch cover 143 holds a mounting stand 60, and the mounting stand 60 holds the fuel container 41. In other words, the fuel container 41 is held by the holding mechanism 59 via the mounting stand 60.
In this manner, a hatch 141 and a hatch cover 143 may be provided in place of the transverse bulkhead opening 81 .

Whether to provide a transverse bulkhead opening 81 as in the first embodiment or a hatch 141 as in the second embodiment as an opening to serve as a route when installing the power generation container 39 and the fuel gas supply container 43 in the engine compartment 11 can be selected as appropriate, taking into account the advantages of each.
For example, the structure having a transverse bulkhead opening 81 as in the first embodiment does not require an opening in the exposed deck 9, so the possibility of water flooding into the machinery space 11 from the exposed deck 9 is lower than in the second embodiment, which is advantageous in terms of preventing flooding due to waves and rainfall.
On the other hand, the second embodiment does not require an opening in the engine room transverse bulkhead 17, so that when the hull 3 collides with another ship or offshore structure and the cargo compartment 13 is flooded, water is less likely to flood into the engine compartment 11 than in the first embodiment, which is advantageous in terms of preventing water flooding in the event of a collision.

Next, the method of loading the fuel container 41, fuel gas supply container 43, and power generation container 39 onto the liquefied gas fueled ship 1a according to the second embodiment will be briefly explained with reference to Figures 14 to 17.

If the installation platform 60 and the fuel container 41 are first loaded on the hatch cover 143, the installation platform 60 and the fuel container 41 are lifted by the quay crane 200 or the like to remove them from the hatch cover 143. Next, the hatch cover 143 is opened as shown in FIG. 14(a). After the hatch cover 143 is opened, the power generation container 39 is lifted from the quay by the quay crane 200, and the planar position of the power generation container 39 is aligned with the planar position of the hatch 141. Furthermore, the hoisting tool of the quay crane 200 is moved in the Z1 direction in FIG. 14(a) to carry the power generation container 39 from the hatch 141 to the fuel gas supply section 27. The carried-in power generation container 39 is temporarily placed on the second deck 23 or the rail 85. The rail 85 is moved to a position where it does not overlap with the deck opening 83 in plan view.

Next, as shown in FIG. 14(b), the power generation container 39 brought into the fuel gas supply section 27 is lifted by the overhead crane 87 and moved in the X1 direction to align the planar position of the power generation container 39 with the planar position of the deck opening 83. In this state, as shown in FIG. 15(a), the hoisting gear of the overhead crane 87 is moved in the Z4 direction to bring the power generation container 39 into the power generation section 29 through the deck opening 83. Furthermore, as shown in FIG. 15(b), the power generation container 39 is grounded on the third deck 25 and held by the holding mechanism 59. After that, the hoisting gear of the overhead crane 87 is removed from the power generation container 39.

Next, the quay crane 200 lifts the fuel gas supply container 43 from the quay, and aligns the planar position of the fuel gas supply container 43 with the planar position of the hatch 141. The rail 85 is also aligned with the planar position of the hatch 141. In this state, the hoisting tool of the quay crane 200 is moved in the Z1 direction as shown in FIG. 16(a) to transport the fuel gas supply container 43 from the hatch 141 to the fuel gas supply section 27 and place it on the rail 85. The fuel gas supply container 43 is then held by the holding mechanism 59 provided on the rail 85. Furthermore, as shown in FIG. 16(b), the rail 85 is moved in the X1 direction to fix the rail 85 in a position spanning the deck opening 83. Once the rail 85 is fixed, the hatch cover 143 is closed.

Next, the quay crane 200 hoists the installation platform 60 from the quay, and aligns the planar position of the long hole 101 of the installation platform 60 with the planar position of the holding mechanism 59 on the hatch cover 143. In this state, the hoisting tool of the quay crane 200 is moved in the Z1 direction as shown in Figure 17(a) to land on the hatch cover 143 and be held by the holding mechanism 59.
Furthermore, the fuel container 41 is hoisted from the quay by the quay crane 200, and the planar position of the long hole 101 of the fuel container 41 is aligned with the planar position of the holding mechanism 59 on the installation base 60. In this state, the hoisting tool of the quay crane 200 is moved in the Z1 direction as shown in FIG.
After that, the onboard piping 91, 93 and power lines are connected, and the installation of the fuel container 41, the fuel gas supply container 43, and the power generation container 39 is completed.

As described above, in the liquefied gas fuelled ship 1a of the second embodiment, the liquefied gas tank 55, the vaporizer 57, the power supply device 78, and the fuel gas supply system 63 are each mounted on a container frame and are detachably arranged in the hull 3. Furthermore, these containers are connected by in-ship piping 91, 93 which are gas pipes.
Therefore, the same effects as those of the first embodiment are achieved.

The present invention has been described above with reference to the embodiments, but the present invention is not limited to the embodiments. It is natural that a person skilled in the art would come up with various modifications and improvements within the scope of the technical concept of the present invention, and these are also included in the present invention.

[0046] 1, 1a: Liquefied gas fuelled ship 3: Hull 5: Ship bottom 5a: Outer bottom plating 7: Side wall 9: Exposed deck 11: Engine compartment 13: Cargo compartment 15: Bow compartment 17: Engine room transverse bulkhead 19: Cargo room transverse bulkhead 21: Inner bottom plating 23: Second deck 25: Third deck 27: Fuel gas supply compartment 29: Power generation compartment 31: Propulsion compartment 33: Deck room 35: Propeller 37: Electric motor 39: Power generation container 41: Fuel container 41a: Liquid discharge outlet 41b: Liquid piping 41c: Gas discharge outlet 42a, 42b: Container frame 43: Fuel gas supply container 43a: Buffer tank 43b: Compressor 43c: Tank side connection part 45: Switchboard 47: Rudder 51: Fuel container frame 55: Liquefied gas tank 57 : Carburetor 59 : Holding mechanism 60 : Installation base 61 : Fuel gas supply container frame 63 : Fuel gas supply system 73 : Power generation container frame 75 : Internal combustion engine 77 : Generator 78 : Power supply unit 81 : Transverse bulkhead opening 83 : Deck opening 85 : Rail 87 : Ceiling crane 91, 93 : Onboard piping 101 : Slot 111 : Twist lock pin 113 : Guide block 115 : Shaft 121 : Cell guide 123 : Lashing bridge 125 : Lashing bar 131 : Battery container 135 : Power storage container frame 137 : Storage battery 141 : Hatch 143 : Hatch cover 200 : Quay crane

Claims (11)

A liquefied gas fuelled ship comprising: an electric motor fixed to a hull for driving a propeller; a power supply unit for generating electricity to be supplied to the electric motor; a liquefied gas tank for storing liquefied gas as fuel for the power supply unit; a vaporizer for vaporizing the liquefied gas; and a fuel gas supply system for supplying the vaporized liquefied gas to the power supply unit,
a fuel container in which the liquefied gas tank and the vaporizer are mounted on a container frame;
a fuel gas supply container in which the fuel gas supply system is mounted on a container frame;
The power supply device comprises a power generation container mounted on a container frame,
A liquefied gas fueled ship characterized in that the fuel container and the fuel gas supply container, and the fuel gas supply container and the power generation container are connected by onboard piping, which is a gas pipe through which the vaporized liquefied gas flows, and are removably held by a holding mechanism provided on the hull. The hull is divided into an engine room transverse bulkhead, in which an engine room and a cargo room are arranged in order from the stern side to the bow side, and a deckhouse is provided on the exposed deck above the engine room.
the power generation container and the fuel gas supply container are disposed in the engine room, below the deckhouse and above the electric motor;
2. The liquefied gas fuelled ship as described in claim 1, wherein the engine room transverse bulkhead is formed with an openable transverse bulkhead opening which serves as a route for installing the power generation container and the fuel gas supply container in the engine space. The engine compartment is divided into three compartments, in the order of a second deck which is a deck arranged inside, and a third deck which is arranged inside and is arranged closer to the bottom of the ship than the second deck, from the exposed deck toward the bottom of the ship: a fuel gas supply compartment in which the fuel gas supply container is mounted, a power generation compartment in which the power generation container is mounted, and a propulsion compartment in which the electric motor is mounted;
the transverse bulkhead opening is provided in a portion of the engine room transverse bulkhead in contact with the fuel gas supply compartment,
The liquefied gas fueled ship according to claim 2, wherein the second deck is provided with a deck opening which serves as a path for installing the power generation container on the third deck. The liquefied gas fuel ship according to claim 3, further comprising a plurality of rails that are removably held on the second deck across the deck opening, and the fuel gas supply system is disposed on the plurality of rails. The liquefied gas fuel ship according to claim 4, wherein the rail has a longitudinal direction facing the ship's length and is horizontally movable in the ship's length direction on the second deck to a position protruding from the transverse bulkhead opening into the cargo compartment. The container frame has long holes at the four corners of the bottom surface,
The holding mechanism includes:
a twist lock pin which is a hook that protrudes upward from a mounting surface of the container frame on the hull, has an outer shape corresponding to an inner circumference of the long hole, and is rotatable around an axis in the vertical direction;
The liquefied gas fuelled ship according to any one of claims 1 to 5, wherein the container frame is held in the hull by inserting the twist lock pin into the long hole and rotating it so that its longitudinal direction intersects with the longitudinal direction of the long hole. The holding mechanism includes:
A cell guide is provided on a mounting surface of the container frame and is a frame surrounding a side surface of the container frame,
A liquefied gas fuelled ship as described in any one of claims 1 to 6, wherein at least one of the fuel container, the power generation container and the fuel gas supply container is held in the hull by installing the container frame on an installation surface surrounded by the cell guide. a battery container in which a storage battery that supplies power to the electric motor and stores the power generated by the power supply device is mounted on a container frame;
The liquefied gas fueled ship according to any one of claims 1 to 7, wherein the battery container is removably held by the holding mechanism provided on the hull. The hull is divided into an engine room transverse bulkhead, in which an engine room and a cargo room are arranged in order from the stern side to the bow side, and a deckhouse is provided on the exposed deck above the engine room.
the power generation container and the fuel gas supply container are disposed in the engine room, below the deckhouse and above the electric motor;
2. The liquefied gas-fueled ship as described in claim 1, wherein, in the exposed deck, above the engine room and in an area where the deckhouse is not provided, there is provided an opening which serves as a route when the power generation container and the fuel gas supply container are installed in the engine room, a hatch which connects the outside of the hull with the engine room, and a hatch cover which is a watertight door which covers the hatch in an openable and closable manner. The engine compartment is divided into three compartments, in the order of a second deck which is a deck arranged inside, and a third deck which is arranged inside and is arranged closer to the bottom of the ship than the second deck, from the exposed deck toward the bottom of the ship: a fuel gas supply compartment in which the fuel gas supply container is mounted, a power generation compartment in which the power generation container is mounted, and a propulsion compartment in which the electric motor is mounted;
The liquefied gas fueled ship according to claim 9, wherein the second deck is provided with a deck opening which is an opening that serves as a path when the power generation container is installed on the third deck. The liquefied gas fuel ship according to claim 9 or 10, wherein the holding mechanism is also provided on the hatch cover in a closed state, and the fuel container is held by the holding mechanism provided on the hatch cover.

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