KR101258324B1 - Reliquefying device installed on liquefied gas carrier - Google Patents

Abstract

The reliquefaction apparatus mounted in a liquefied gas carrier ship is equipped with the compressor which compresses the boil-off gas of flammable liquefied gas, and the explosion-proof motor which drives a compressor. By using the explosion-proof motor, even if an explosion occurs inside the explosion-proof motor, the container of the explosion-proof motor is not destroyed, and the flame is prevented from popping out of the container and flammable with flammable gas. Therefore, it is not necessary to arrange the explosion-proof motor and the compressor in each room partitioned by a partition. Therefore, the freedom degree of in-line arrangement | positioning of a reliquefaction apparatus becomes high.

Description

RELIQUEFYING DEVICE INSTALLED ON LIQUEFIED GAS CARRIER}

The present invention relates to a reliquefaction apparatus, a liquefied gas carrier, and a method for drying a liquefied gas carrier, which is mounted on a liquefied gas carrier that carries flammable liquefied gas such as liquefied petroleum gas (LPG) or liquefied natural gas (LNG). It is about.

Referring to Fig. 1, a conventional LPG line 101 will be described. The LPG ship 101 includes a plurality of LPG tanks 102 for storing LPG, and a plurality of reliquefaction devices 106 for reliquefying the LPG's boil-off gas. The LPG tank 102 is formed below the deck. The reliquefaction apparatus 106 includes a compressor 161 for compressing the boil off gas, a condenser 162 connected to the compressor 161, an expansion valve 163 connected to the condenser 162, and a compressor 161. ) Is provided with a motor 181 for driving.

The plurality of compressors 161 each of the plurality of reliquefaction apparatuses 106 are disposed in the gas compressor room 103 formed on the deck. The plurality of motors 181, which the plurality of reliquefaction apparatuses 106 each have, are disposed in the motor room 104 formed on the deck. The gas compressor room 103 and the motor room 104 are partitioned off by the partition wall 105. The motor 181 and the compressor 161 are connected by the intermediate shaft 183 which penetrates the partition 105. The partition seal 184 is formed so as to seal the gap between the partition wall 105 and the intermediate shaft 183.

The motor 118 and the compressor 161 which handle combustible LPG which can be a ignition source are subject to the following restrictions from a safety point of view.

It is necessary to form a partition 105 between the motor 181 and the compressor 161, and arrange the motor 181 and the compressor 161 in different rooms, that is, the motor room 104 and the gas compressor room 103, respectively. There is. Since the motor 181 and the compressor 161 are connected with the partition 105 interposed therebetween, a special partition wall penetrating device such as the intermediate shaft 183 and the partition seal 184 is required. Since it is necessary to make the motor room 104 into the safety section which LPG does not invade, the suction place of the ventilation fan of the motor room 104 is limited, and the installation place of the motor room 104 is limited. Since it is necessary to form the partition 105 between the motor 181 and the compressor 161, the reliquefaction apparatus 106 cannot be arrange | positioned freely in a line. Since it is necessary to install the motor 181, the compressor 161, and the intermediate shaft 183 in a narrow space in a line, compared with the case where the reliquefaction apparatus 106 is assembled in a factory and installed in a line, working time This is a lot needed. In order to facilitate the adjustment of the shaft center between the motor 181 and the compressor 161, the intermediate shaft 183 needs to be provided with a flexible seam such as a rubber elastic seam.

Japanese Patent Laid-Open No. 9-221098 discloses a conventional LPG line. Japanese Laid-Open Patent Publication No. 2009-204080 discloses a conventional LNG carrier.

As far as the present inventors know, there is no example in which an explosion-proof motor is applied to a ship.

Patent Document 1: Japanese Patent Application Laid-Open No. 9-221098 Patent Document 2: Japanese Unexamined Patent Publication No. 2009-204080

An object of the present invention is to provide a reliquefaction apparatus, a liquefied gas carrier, and a method of drying a liquefied gas carrier that are mounted on a liquefied gas carrier that has a high degree of freedom in in-line arrangement of the reliquefaction apparatus.

The reliquefaction apparatus mounted on the liquefied gas carrier ship by the 1st viewpoint of this invention is equipped with the compressor which compresses the boil off gas of flammable liquefied gas, and the explosion-proof motor which drives the said compressor.

By using the explosion-proof motor, even if an explosion occurs inside the explosion-proof motor, the container of the explosion-proof motor is not destroyed, and the flame is prevented from popping out of the container and flammable with flammable gas. Therefore, it is not necessary to arrange the explosion-proof motor and the compressor in each room partitioned by a partition. Therefore, the degree of freedom of in-line arrangement of the reliquefaction apparatus increases.

Preferably, the reliquefaction apparatus further includes a base sheet provided with the compressor and the explosion-proof motor.

Preferably, the reliquefaction apparatus further includes a gas leak detector and a shutoff valve that blocks supply of the boil-off gas to the compressor when the gas leak detector detects a gas leak of the liquefied gas. do.

Preferably, the reliquefaction apparatus further includes a temperature sensor for detecting a motor temperature of the explosion-proof motor, and an alarm for generating an alarm when the motor temperature is higher than a first reference temperature.

Preferably, the reliquefaction apparatus further includes a motor control device for stopping the explosion-proof motor when the motor temperature is higher than the second reference temperature.

Preferably, the reliquefaction apparatus further includes a temperature sensor for detecting a motor temperature of the explosion-proof motor, and a motor control device for stopping the explosion-proof motor when the motor temperature is higher than a reference temperature.

The reliquefaction apparatus may include a motor covered with an explosion-proof box instead of the explosion-proof motor.

By covering the perimeter of the motor with an explosion-proof box, the explosion-proof box is not destroyed even if the motor explodes, and the flame is prevented from popping out of the explosion-proof box and being flammable with flammable gas. Therefore, it is not necessary to arrange a motor and a compressor in each room partitioned by a partition. Therefore, the degree of freedom of in-line arrangement of the reliquefaction apparatus increases.

Preferably, a cooling fin is formed in the explosion-proof box.

A liquefied gas carrier ship according to a second aspect of the present invention includes a plurality of tanks for storing flammable liquefied gas, and a plurality of reliquefaction devices for liquefying the boil-off gas of the liquefied gas. Each of the plurality of reliquefaction apparatuses includes a compressor for compressing the boil-off gas and an explosion-proof motor for driving the compressor.

Preferably, the liquefied gas carrier ship is configured to switch between a preliminary reliquefaction apparatus, a state in which the preliminary reliquefaction apparatus is not connected to any of the plurality of tanks, and a state connected to any one of the plurality of tanks. A piping system is further provided. The plurality of reliquefaction apparatuses are each connected to the plurality of tanks. The preliminary reliquefaction apparatus includes a compressor for compressing the boil-off gas and an explosion-proof motor for driving the compressor.

Preferably, the plurality of tanks include a first tank and a second tank adjacent to each other. The plurality of reliquefaction apparatuses includes a first reliquefaction apparatus and a second reliquefaction apparatus. The liquefied gas carrier ship further includes a BOG mother pipe connecting the first tank and the second tank, and an RLG mother pipe connecting the first tank and the second tank. A first valve or first spool piece is formed in the BOG capillary. The BOG capillary connects the BOG capillary first tank side portion that connects the first valve or the first spool piece to the first tank, and connects the first valve or the first spool piece to the second tank. BOG capillary second tank side portion. A second valve or second spool piece is formed in the RLG capillary. The RLG capillary connects the RLG capillary first tank side portion that connects the second valve or the second spool piece to the first tank, and connects the second valve or the second spool piece to the second tank. RLG capillary second tank side portion. Each of the plurality of reliquefaction apparatuses includes a BOG pipe for supplying the boil off gas to the compressor, and an RLG pipe for returning the reliquefied gas in which the boil off gas is reliquefied. The BOG pipe of the first reliquefaction apparatus is connected to the BOG capillary first tank side portion. The BOG pipe of the second reliquefaction apparatus is connected to the BOG capillary second tank side portion. The RLG piping of the first reliquefaction apparatus is connected to the RLG capillary first tank side portion. The RLG piping of the second reliquefaction apparatus is connected to the RLG mother pipe second tank side portion.

Preferably, the liquefied gas carrier ship includes a BOG capillary, a valve or spool piece group formed in the BOG capillary such that the BOG capillary is divided into a plurality of BOG capillary portions, an RLG capillary, and the RLG capillary comprises a plurality of RLG capillary tubes. A valve or spool piece group formed in the RLG capillary to be divided into portions, a plurality of tank side BOG piping for connecting the plurality of tanks to the plurality of BOG capillary portions, respectively, and the plurality of tanks respectively for the plurality of RLG capillaries A plurality of tank side RLG piping connected to the part is further provided. A valve or spool piece is formed in each of the plurality of tank side BOG pipes. A valve or spool piece is formed in each of the plurality of tank side RLG pipes. Each of the plurality of reliquefaction apparatuses includes a reliquefaction apparatus side BOG piping for supplying the boil off gas to the compressor, and a reliquefaction apparatus side RLG piping for returning the reliquefaction gas in which the boil off gas is reliquefied. do. The plurality of reliquefaction apparatuses are respectively connected to the plurality of BOG mother pipe portions via the reliquefaction apparatus side BOG piping. The plurality of reliquefaction apparatuses are respectively connected to the plurality of RLG mother pipe portions via the reliquefaction apparatus side RLG piping.

Preferably, the plurality of reliquefaction apparatuses are each equipped with the plurality of tanks.

Each of the plurality of reliquefaction apparatuses may include a motor covered with an explosion-proof box instead of the explosion-proof motor.

Each of the plurality of reliquefaction apparatuses and the preliminary reliquefaction apparatus may include a motor covered with an explosion-proof box in place of the explosion-proof motor.

According to a third aspect of the present invention, there is provided a method for drying a liquefied gas carrier, including assembling a reliquefaction apparatus for reliquefying a boil off gas of a flammable liquefied gas, and installing the reliquefaction apparatus in a hull or hull block. Equipped. The step of assembling the reliquefaction apparatus includes installing a compressor and an explosion-proof motor on the base sheet for compressing the boil-off gas, and connecting the compressor and the explosion-proof motor.

Preferably, the assembling of the reliquefaction apparatus comprises: installing the compressor for compressing the boil-off gas and the explosion-proof motor on the base sheet, and connecting the compressor and the explosion-proof motor. Instead, there is provided a compressor for compressing the boil-off gas, a motor and an explosion-proof box covering the motor, on the base sheet, and connecting the compressor and the motor.

According to the present invention, there is provided a method for drying a reliquefaction apparatus, a liquefied gas carrier and a liquefied gas carrier that are mounted on a liquefied gas carrier that has a high degree of freedom in in-line arrangement of the reliquefaction apparatus.

The above objects, other objects, effects, and features of the present invention will become more apparent from the description of the embodiments in conjunction with the accompanying drawings.
1 is a schematic diagram of a conventional LPG vessel.
2 is a schematic view of a reliquefaction apparatus according to a first embodiment of the present invention.
3 is a schematic view of a reliquefaction apparatus according to a modification of the first embodiment.
4 is a schematic diagram of a reliquefaction apparatus according to a second embodiment of the present invention.
5 is a schematic diagram of a reliquefaction apparatus according to a third embodiment of the present invention.
6 is a cross-sectional view of a reliquefaction apparatus according to a modification of the third embodiment.
7 is a schematic diagram of a liquefied gas carrier ship according to a fourth embodiment of the present invention.
8 is a schematic diagram of a liquefied gas carrier ship according to a fifth embodiment of the present invention.
9 is a schematic diagram of a liquefied gas carrier ship according to a sixth embodiment of the present invention.
10 is a schematic diagram of a liquefied gas carrier ship according to a seventh embodiment of the present invention.
It is a schematic diagram of the reliquefaction apparatus concentration arrangement area of the liquefied gas carrier ship which concerns on 7th Embodiment.
12 is a schematic view of a reliquefaction apparatus concentrated placement zone according to a first modification of the seventh embodiment.
FIG. 13 is a schematic view of a reliquefaction apparatus concentrated placement zone according to a second modification of the seventh embodiment. FIG.
FIG. 14 is a schematic view of a reliquefaction apparatus concentrated placement zone according to a third modification of the seventh embodiment. FIG.
FIG. 15 is a schematic diagram of a reliquefaction apparatus concentrated placement zone according to a fourth modification of the seventh embodiment. FIG.
FIG. 16 is a schematic diagram of a reliquefaction apparatus concentration arranging zone according to a fifth modification of the seventh embodiment.

Carrying out the invention  Form for

EMBODIMENT OF THE INVENTION With reference to an accompanying drawing, the form for implementing the reliquefaction apparatus, the liquefied gas carrier ship, and the liquefied gas carrier ship which are mounted on the liquefied gas carrier ship by this invention is demonstrated below.

(First Embodiment)

With reference to FIG. 2, the reliquefaction apparatus 6 which concerns on 1st Embodiment of this invention is demonstrated. The reliquefaction apparatus 6 is mounted in the liquefied gas carrier which carries combustible liquefied gas, such as LPG and LNG, and reliquefies the boil-off gas of liquefied gas. The reliquefaction apparatus 6 includes a base sheet 60, a compressor 61 for compressing the boil-off gas, a condenser 62 connected to the compressor 61, and an expansion valve connected to the condenser 62. 63, a BOG pipe 64 for supplying the boil off gas from the tank to the compressor 61, an RLG pipe 65 for returning the reliquefied gas from which the boil off gas has been reliquefied to the tank, and a compressor ( The explosion-proof motor 66 which drives 61, and the spacer 67 which connects the explosion-proof motor 66 and the compressor 61 are provided. The spacer 67 is formed for distance adjustment between the explosion-proof motor 66 and the compressor 61.

The compressor 61, the condenser 62, the expansion valve 63, and the explosion-proof motor 66 are provided on the base sheet 60, whereby the reliquefaction apparatus 6 is unitized.

According to the present embodiment, by using the explosion-proof motor 66, even if an explosion occurs inside the explosion-proof motor 66, the container of the explosion-proof motor 66 is not destroyed, and the flame pops out of the container and is flammable with flammable gas. Is prevented. Therefore, it is not necessary to arrange the explosion-proof motor 66 and the compressor 61 in each room partitioned by a partition.

Since no partition wall is formed between the explosion-proof motor 66 and the compressor 61, a special partition penetrating device such as an intermediate shaft and a partition wall seal is unnecessary, and an explosion-proof motor 66 is not used without using a flexible joint such as a rubber elastic joint. And the compressor 61 can be connected.

Since it is not necessary to arrange the explosion-proof motor 66 and the compressor 61 in each room partitioned by a partition, the degree of freedom of in-line arrangement of the reliquefaction apparatus 6 increases. Since the reliquefaction apparatus 6 can be placed in an empty space, the space in the line can be effectively used.

Since the explosion-proof motor 66 and the compressor 61 do not need to be arranged in each room partitioned by a partition, the explosion-proof motor 66 and the compressor 61 can be arrange | positioned near. Therefore, the operation of the reliquefaction apparatus 6 can be centrally managed at one point. The inspection and maintenance of the reliquefaction apparatus 6 also become easy.

By connecting the explosion-proof motor 66 and the compressor 61 via the spacer 67, the design change at the time of changing the model of the explosion-proof motor 66 can be minimized.

However, when the space | interval of the explosion-proof motor 66 and the compressor 61 is predetermined, as shown in FIG. 3, even if the explosion-proof motor 66 and the compressor 61 are connected directly, without the spacer 67, do.

The reliquefaction apparatus 6 may not be provided with the expansion valve 63, and does not need to be equipped with the expansion valve 63 and the capacitor | condenser 62. FIG.

Since it is not necessary to arrange the explosion-proof motor 66 and the compressor 61 in each room partitioned by the partition, the drying method of the liquefied gas carrier ship which concerns on 1st Embodiment described below is possible.

The drying method of the liquefied gas carrier ship which concerns on 1st Embodiment is equipped with the step of assembling the reliquefaction apparatus 6, and providing the reliquefaction apparatus 6 to the ship body 10 (to be described later). The step of assembling the reliquefaction apparatus 6 is performed outside the ship, such as a factory. The step of assembling the reliquefaction apparatus 6 includes the steps of installing the compressor 61 and the explosion-proof motor 66 on the base sheet 60, and the compressor so that the explosion-proof motor 66 can drive the compressor 61. 61 and an explosion-proof motor 66 are provided. In the step of connecting the compressor 61 and the explosion-proof motor 66, the explosion-proof motor 66 and the compressor 61 are connected with or without the spacer 67.

According to the drying method of the liquefied gas carrier ship which concerns on this embodiment, the explosion-proof motor 66 and the compressor 61 need only be carried in and fixed to the ship body 10 for every base seat 60, and the ship body 10 may be fixed. There is no need to adjust the shaft center between the explosion-proof motor 66 and the compressor 61. Therefore, the work in the ship body 10 is reduced, and the drying cost of a liquefied gas carrier ship is reduced.

Instead of installing the reliquefaction apparatus 6 to the hull 10, the step of installing the reliquefaction apparatus 6 to the hull block and assembling the hull 10 from the hull block are performed. The cost of drying the carrier is further reduced.

(Second Embodiment)

With reference to FIG. 4, the reliquefaction apparatus 6 which concerns on 2nd Embodiment of this invention is demonstrated. The reliquefaction apparatus 6 which concerns on this embodiment is a gas leak detector 71, the shutoff valve 72, the temperature sensor 73, the alarm 74, to the reliquefaction apparatus 6 which concerns on 1st Embodiment. And a motor control device 75 is added.

The shutoff valve 72 is formed in the BOG piping 64. The shutoff valve 72 cuts off the supply of the boil-off gas to the compressor 61 when the gas leak detector 71 detects a gas leak of the liquefied gas.

The temperature sensor 73 detects the surface temperature or the winding temperature of the explosion-proof motor 66 as the motor temperature. The alarm 74 generates an alarm when the motor temperature is higher than the first reference temperature to inform the source of the abnormality. The motor control apparatus 75 automatically stops the explosion-proof motor 66 when the motor temperature is higher than the second reference temperature. Here, it is preferable that a 2nd reference temperature is higher than a 1st reference temperature.

Reliability for preventing gas explosion by stopping supply of the boil-off gas to the compressor 61 based on detection of gas leakage, generating an alarm based on the motor temperature, and stopping the explosion-proof motor 66 based on the motor temperature. This is improved.

Further, any two or only one of the shutoff of the supply of the boil-off gas to the compressor 61 based on the detection of the gas leak, the generation of an alarm based on the motor temperature, and the stop of the explosion-proof motor 66 based on the motor temperature May be executed.

(Third Embodiment)

With reference to FIG. 5, the reliquefaction apparatus 6 which concerns on 3rd Embodiment of this invention is demonstrated. The reliquefaction apparatus 6 which concerns on this embodiment is equipped with the motor 81 covered by the explosion-proof box 82 instead of the explosion-proof motor 66, and replaces the spacer 67 and the intermediate shaft 83 and a partition. A seal 84. The explosion-proof box 82 covers the motor 81 individually. That is, the explosion-proof box 82 covers only one motor 81. The motor 81 and the compressor 61 are connected by the intermediate shaft 83 which penetrates the explosion-proof box 82. The intermediate shaft 83 has flexible seams such as rubber elastic seams. The partition seal 84 is formed so as to seal the gap between the explosion-proof box 82 and the intermediate shaft 83.

According to this embodiment, by covering the periphery of the motor 81 with the explosion-proof box 82, even if the motor 81 explodes, the explosion-proof box 82 is not destroyed and a flame jumps out of the explosion-proof box 82 Ignition and flammable gas are prevented. Therefore, it is not necessary to arrange the motor 81 and the compressor 61 in each room partitioned by a partition. Therefore, the degree of freedom of in-line arrangement of the reliquefaction apparatus 6 increases.

Since it is not necessary to arrange the motor 81 and the compressor 61 in each room partitioned by a partition, the motor 81 and the compressor 61 can be arrange | positioned closely. Therefore, the operation of the reliquefaction apparatus 6 can be centrally managed at one point. The inspection and maintenance of the reliquefaction apparatus 6 also become easy.

According to this embodiment, the length of the intermediate shaft 83 can be made shorter than the intermediate shaft 183 which penetrates the partition 105.

As shown in FIG. 6, it is preferable to form the cooling fin 85 in the explosion-proof box 81. The cooling fin 85 effectively dissipates heat generated during operation of the motor 81 in the air, thereby preventing the temperature of the motor 81 from rising.

Since it is not necessary to arrange the motor 81 and the compressor 61 in each room partitioned by a partition, the drying method of the liquefied gas carrier ship which concerns on 3rd Embodiment described below is possible.

The drying method of the liquefied gas carrier ship which concerns on 3rd Embodiment is equipped with the step of assembling the reliquefaction apparatus 6, and providing the reliquefaction apparatus 6 to the ship body 10 (to be described later). The step of assembling the reliquefaction apparatus 6 is performed outside the ship, such as a factory. Assembling the reliquefaction apparatus 6 includes installing the explosion-proof box 82 covering the compressor 61, the motor 81, and the motor 81 to the base sheet 60, and the motor 81. And connecting the compressor 61 and the motor 81 so that the compressor can drive the compressor 61. In the step of connecting the compressor 61 and the motor 81, the motor 81 and the compressor 61 are connected via the intermediate shaft 83.

According to the drying method of the liquefied gas carrier ship which concerns on this embodiment, the motor 81, the explosion-proof box 82, and the compressor 61 need only be carried in and fixed to the ship body 10 for every base sheet 60, There is no need to adjust the shaft center between the motor 81 and the compressor 61 in the hull 10. Therefore, the work in the ship body 10 is reduced, and the drying cost of a liquefied gas carrier ship is reduced.

Instead of installing the reliquefaction apparatus 6 to the hull 10, the step of installing the reliquefaction apparatus 6 to the hull block and assembling the hull 10 from the hull block are performed. The cost of drying the carrier is further reduced.

(Fourth Embodiment)

With reference to FIG. 7, the liquefied gas carrier ship 1 which concerns on 4th Embodiment of this invention is demonstrated. The liquefied gas carrier ship 1 includes a hull 10, a plurality of tanks 2-1 to 2-N storing liquefied gas, and a plurality of reliquefaction devices 6 to liquefy a boiloff gas of liquefied gas. -1-6-N), the reliquefaction apparatus 6- (N + 1), and the piping system 3 are provided. The tanks 2-1 to 2-N, the reliquefaction apparatuses 6-1 to 6-N, and the reliquefaction apparatus 6- (N + 1) are mounted on the hull 10. The hull 10 includes a bow 11, a stern 12, and a deck 13. The tanks 2-1 to 2-N are formed below the deck 13 and are arranged along the hull 10 front-rear direction (bow stern direction). The plurality of reliquefaction apparatuses 6-1 to 6-N and the reliquefaction apparatus 6- (N + 1) are formed on the deck 13. Reliquefaction apparatus 6- (N + 1) functions as a preliminary reliquefaction apparatus. Each of the plurality of reliquefaction apparatuses 6-1 to 6-N and the reliquefaction apparatus 6- (N + 1) is a reliquefaction apparatus 6 according to any of the above embodiments. Therefore, the some reliquefaction apparatus 6-1-6-N and the reliquefaction apparatus 6- (N + 1) can be arrange | positioned at the ship body 10 freely.

Reliquefaction apparatuses 6-1 to 6-N are connected to tanks 2-1 to 2-N, respectively. The reliquefaction apparatuses 6-1 to 6-N reliquefy the boiloff gas from the tanks 2-1 to 2-N, respectively, to produce a reliquefaction gas, and the reliquefaction gas to each tank (2- 1 to 2-N).

The reliquefaction apparatuses 6-1 to 6-N are dispersed and arranged, and are equipped with the tanks 2-1 to 2-N, respectively. In other words, the reliquefaction apparatuses 6-1 to 6-N are disposed on the tanks 2-1 to 2-N, respectively.

The piping system 3 has a state in which the preliminary reliquefaction apparatus 6- (N + 1) is not connected to any of the tanks 2-1 to 2-N and the tanks 2-1 to 2-N. It is comprised so that the state connected to any tank among them may be switched. More specifically, the piping system 3 includes the BOG mother pipe 31, the RLG mother pipe 32, the plurality of BOG pipes 33-1 to 33 -N, and the plurality of RLG pipes 34-1 to. 34-N). The BOG mother pipe 31 and the RLG mother pipe 32 extend in the front-rear direction of the hull 10. In each of the BOG pipes 33-1 to 33-N, a valve or a spool piece 40 is formed. Each of the RLG pipes 34-1 to 34-N is provided with a valve or spool piece 40. The BOG mother pipe 31 is connected to the tanks 2-1 to 2-N via the BOG pipes 33-1 to 33-N, respectively. The RLG mother pipe 32 is connected to the tanks 2-1 to 2-N via RLG piping 34-1 to 34-N, respectively. The BOG piping 64 and the RLG piping 65 of the preliminary reliquefaction apparatus 6- (N + 1) are connected to the BOG mother pipe 31 and the RLG mother pipe 32, respectively.

If the reliquefaction apparatus 6-L has failed in the reliquefaction apparatuses 6-1 to 6-N, the piping system 3 has a preliminary reliquefaction apparatus 6- (N + 1) having a tank 2-L. Takes the state connected to At this time, the boil-off gas is supplied from the tank 2-L to the preliminary reliquefaction apparatus 6- (N + 1) via the BOG piping 33-L and the BOG capillary 31, and preliminary reliquefaction. Apparatus 6- (N + 1) reliquefies the boil off gas to produce a reliquefaction gas, and the reliquefaction gas is supplied from the preliminary reliquefaction apparatus 6- (N + 1) to the RLG capillary 32 and RLG. The tank is returned to the tank 2-L via the pipe 34-L.

(Fifth Embodiment)

With reference to FIG. 8, the liquefied gas carrier ship 1 which concerns on 5th Embodiment of this invention is demonstrated. The liquefied gas carrier ship 1 which concerns on this embodiment is the same as the liquefied gas carrier ship 1 which concerns on 4th embodiment except the following description.

In the piping system 3 which concerns on this embodiment, the BOG capillary 31 connects the tank 2-1 and the tank 2-2, and the RLG capillary 32 is the tank 2-1 and the tank. (2-2) is connected. The valve or spool piece 40 is formed in the BOG mother pipe 31. The BOG capillary 31 connects the BOG capillary portion 31-1 that connects the valve or spool piece 40 and the tank 2-1, and the valve or spool piece 40 and the tank 2-2. BOG capillary portion 31-2. The valve or spool piece 40 is formed in the RLG mother pipe 32. The RLG capillary 32 connects the valve or spool piece 40 and the tank 2-1 to the RLG capillary part 32-1 connecting the valve or the spool piece 40 and the tank 2-1. RLG capillary portion 32-2. The BOG piping 64 of the reliquefaction apparatus 2-1 is connected to the BOG mother pipe portion 31-1. The BOG piping 64 of the reliquefaction apparatus 2-2 is connected to the BOG mother pipe portion 31-2. The RLG piping 65 of the reliquefaction apparatus 2-1 is connected to the RLG mother pipe portion 32-1. The RLG piping 65 of the reliquefaction apparatus 2-2 is connected to the RLG mother pipe portion 32-2.

According to this embodiment, when both of the reliquefaction apparatuses 2-1 and 2-2 operate normally, the valve or spool piece 40 formed in the BOG mother pipe 31 is in a closed state, and the RLG mother pipe 32 The valve or spool piece 40 formed in FIG. 9 is in an open state. At this time, the reliquefaction apparatus 2-1 reliquefies the boil-off gas from the tank 2-1, returns the reliquefaction gas to the tank 2-1, and the reliquefaction apparatus 2-2 is a tank. The liquefied gas from (2-2) is liquefied and the reliquefied gas is returned to the tank (2-2). When one of the reliquefaction apparatuses 2-1 and 2-2 has failed, the valve or spool piece 40 installed in the BOG mother pipe 31 is opened, and the valve or spool piece installed in the RLG mother pipe 32 ( 40) becomes an open state. Then, the other, which has not failed, reliquefies the boil-off gas from the reliquefaction tanks 2-1 and 2-2, and returns the reliquefaction gas to the reliquefaction tanks 2-1 and 2-2.

(Sixth Embodiment)

With reference to FIG. 9, the liquefied gas carrier ship 1 which concerns on 6th Embodiment of this invention is demonstrated. The liquefied gas carrier ship 1 which concerns on this embodiment is the same as the liquefied gas carrier ship 1 which concerns on 4th embodiment except the following description.

In the piping system 3 according to the present embodiment, a group of valves or spool pieces 40 is attached to the BOG capillary 31 so that the BOG capillary 31 is divided into a plurality of BOG capillary portions 31-1 to 31 -N. Is formed, and a group of valves or spool pieces 40 is formed in the RLG capillary 32 so that the RLG capillary 32 is divided into a plurality of RLG capillary portions 32-1 to 32-N. The BOG piping 33-1 to 33-N connects the tanks 2-1 to 2-N to the BOG capillary portions 31-1 to 31-N, respectively. The RLG piping 34-1 to 34-N connects the tanks 2-1 to 2-N to the RLG capillary portions 32-1 to 32-N, respectively. A valve or spool piece 40 is formed in each of the BOG pipes 33-1 to 33-N. A valve or spool piece 40 is formed in each of the RLG pipes 34-1 to 34-N. The reliquefaction apparatuses 6-1 to 6-N are connected to the BOG capillary portions 31-1 to 31-N via the BOG pipe 64, respectively. The reliquefaction apparatuses 6-1 to 6-N are connected to the RLG mother pipe portions 32-1 to 32-N via the RLG piping 65, respectively. In this embodiment, the preliminary reliquefaction apparatus 6- (N + 1) is not formed.

According to this embodiment, arbitrary tanks in tanks 2-1 to 2-N can be connected to any reliquefaction apparatus in reliquefaction apparatuses 6-1 to 6-N. Moreover, according to this embodiment, since a mother tube is divided into many parts, flexibility increases.

(Seventh Embodiment)

With reference to FIG. 10, the liquefied gas carrier ship 1 which concerns on 7th Embodiment of this invention is demonstrated. The liquefied gas carrier ship 1 which concerns on this embodiment is the same as the liquefied gas carrier ship 1 which concerns on any of 4th-6th embodiment except the following description. According to this embodiment, the reliquefaction apparatus is arrange | positioned centrally at one point.

In the present embodiment, the reliquefaction apparatuses 6-1 to 6-N are concentrated in the reliquefaction apparatus concentration arrangement region 5 formed on the deck 13. In addition, when the liquefied gas carrier ship 1 which concerns on this embodiment respond | corresponds to the liquefied gas carrier ship which concerns on 4th embodiment, the reliquefaction apparatus 6-1-6- (N in the reliquefaction apparatus concentrated arrangement area | region 5). +1)) are concentrated. Hereinafter, although the case where the reliquefaction apparatus 6-1-6-N is arrange | positioned intensively in the reliquefaction apparatus concentrated arrangement area 5 is described, the reliquefaction apparatus 6-6- in the reliquefaction apparatus concentrated arrangement area 5 is demonstrated. The same applies to the case where 1 to 6- (N + 1)) are concentrated.

With reference to FIG. 11, in the reliquefaction apparatus concentrated arrangement area | region 5, the reliquefaction apparatus 6-1-6-N are arrange | positioned in 1 row. That is, the reliquefaction apparatuses 6-1 to 6-N are arranged along one straight line extending in the horizontal direction of the hull 10.

In each of the reliquefaction apparatuses 6-1 to 6-N, the motor 66 or 81 is disposed at the front side (bow 11 side), and the compressor 61 is at the rear side (stern 12 ) Side), the motor 66 or 81 may be arrange | positioned at the back side, and the compressor 61 may be arrange | positioned at the front side. Whether the motor 66 or 81 is disposed on the front side or the rear side may be unified in the reliquefaction apparatuses 6-1 to 6-N or may not be unified. Adjacent reliquefaction apparatuses can make compact the reliquefaction apparatus concentrated arrangement area | region 5 by differentiating which motor 66 or 81 is arrange | positioned in the front side or the rear side. This is the same also about FIGS. 12-16 mentioned later.

(1st modification of 7th Embodiment)

With reference to FIG. 12, in the reliquefaction apparatus concentrated arrangement area | region 5 which concerns on the 1st modification of 7th Embodiment, although the reliquefaction apparatus 6-1-6-N are arrange | positioned in a horizontal row, neighboring ashes The liquefaction apparatus is arrange | positioned shifted back and forth.

(2nd modification of 7th Embodiment)

With reference to FIG. 13, in the reliquefaction apparatus concentrated arrangement area | region 5 which concerns on 2nd modified example of 7th Embodiment, the reliquefaction apparatus 6-1-6-N is BOG capillary 31 and RLG capillary ( 32) It is arranged in a horizontal row so as to be divided into both left and right sides with the interposed therebetween. Reliquefaction apparatus 6-1-6-N may be arrange | positioned so that a neighboring reliquefaction apparatus may not shift back and forth, and a neighboring reliquefaction apparatus may shift and arrange | position back and forth.

(3rd modification of 7th Embodiment)

With reference to FIG. 14, the reliquefaction apparatus 6-1-6-N is arrange | positioned in two horizontal rows in the reliquefaction apparatus concentrated arrangement area | region 5 which concerns on 3rd modified example of 7th Embodiment. That is, the reliquefaction apparatuses 6-1 to 6-N are arranged along two straight lines extending in the horizontal direction of the hull 10.

(4th modification of 7th Embodiment)

With reference to FIG. 15, the reliquefaction apparatus 6-1-6-N is arrange | positioned in the horizontal multiple row in the reliquefaction apparatus concentrated arrangement area | region 5 which concerns on 4th modified example of 7th Embodiment. That is, the reliquefaction apparatuses 6-1 to 6-N are arranged along three or more straight lines extending in the horizontal direction of the hull 10.

(Fifth modification of the seventh embodiment)

With reference to FIG. 16, the reliquefaction apparatus 6-1-6-N is arrange | positioned at 1 column in the reliquefaction apparatus concentrated arrangement area | region 5 which concerns on 5th modified example of 7th Embodiment. The reliquefaction apparatuses 6-1 to 6-N are arranged along one straight line extending in the front-rear direction of the hull 10. In addition, the reliquefaction apparatuses 6-1 to 6-N may be arranged in a plurality of vertical rows.

As mentioned above, although this invention was demonstrated with reference to embodiment, this invention is not limited to the said embodiment. Various changes can be made to the above embodiment. The above embodiments can be combined with each other.

This application claims the priority based on Japanese Patent Application No. 2010-026448 for which it applied on February 9, 2010, and introduces all of the indication here.

Claims (17)

A plurality of tanks storing flammable liquefied gas;
A plurality of reliquefaction apparatuses for reliquefying the boil off gas of the liquefied gas,
Liquefied gas provided with the piping system which switches the state in which the preliminary reliquefaction apparatus as one of the said plurality of reliquefaction apparatuses is not connected to any of the said some tank, and the state connected to any tank of the said some tank. Each of the plurality of reliquefaction devices of the carrier
Compressor which compresses the boil-off gas of flammable liquefied gas,
An explosion-proof motor for driving the compressor;
And a base sheet provided with the compressor and the explosion-proof motor. The method of claim 1,
Gas leak detector,
And a shut-off valve that cuts off the supply of the boil-off gas to the compressor when the gas leak detector detects a gas leak of the liquefied gas. The method of claim 1,
A temperature sensor detecting a motor temperature of the explosion-proof motor;
And an alarm for generating an alarm when the motor temperature is higher than the first reference temperature. The method of claim 3, wherein
And a motor control device for stopping the explosion-proof motor when the motor temperature is higher than a second reference temperature. The method of claim 1,
A temperature sensor detecting a motor temperature of the explosion-proof motor;
And a motor control device for stopping the explosion-proof motor when the motor temperature is higher than a reference temperature. The method of claim 1,
A reliquefaction apparatus provided with the motor covered by the explosion-proof box instead of the said explosion-proof motor. The method according to claim 6,
Reliquefaction apparatus formed with a cooling fin in the explosion-proof box. A plurality of tanks storing flammable liquefied gas;
A plurality of reliquefaction apparatuses for reliquefying the boil off gas of the liquefied gas,
A preliminary reliquefaction device,
And a piping system for switching the state in which the preliminary reliquefaction device is not connected to any of the plurality of tanks and the state connected to any one of the plurality of tanks,
Each of the plurality of reliquefaction devices
A compressor for compressing the boil-off gas
An explosion-proof motor for driving the compressor,
The plurality of reliquefaction apparatuses are each connected to the plurality of tanks,
The preliminary reliquefaction apparatus,
A compressor for compressing the boil-off gas,
A liquefied gas carrier ship having an explosion-proof motor for driving the compressor. A plurality of tanks for storing the flammable liquefied gas, and the plurality of tanks include a first tank and a second tank adjacent to each other;
A plurality of reliquefaction apparatuses for reliquefying the boil off gas of the liquefied gas, and the plurality of reliquefaction apparatuses include a first reliquefaction apparatus and a second reliquefaction apparatus,
BOG capillary connecting the first tank and the second tank,
An RLG mother pipe connecting said first tank and said second tank,
Each of the plurality of reliquefaction devices
A compressor for compressing the boil-off gas
An explosion-proof motor for driving the compressor,
A first valve or first spool piece is formed in the BOG capillary,
The BOG capillary,
A BOG capillary first tank side portion connecting the first valve or the first spool piece and the first tank,
A BOG capillary second tank side portion connecting said first valve or said first spool piece and said second tank,
A second valve or second spool piece is formed in the RLG capillary,
The RLG capillary,
An RLG capillary first tank side portion connecting the second valve or the second spool piece and the first tank,
An RLG capillary second tank side portion connecting said second valve or said second spool piece and said second tank,
Each of the plurality of reliquefaction apparatus,
BOG piping for supplying the boil off gas to the compressor,
RLG piping for returning the reliquefied gas re-liquefied the boil off gas,
The BOG pipe of the first reliquefaction apparatus is connected to the BOG capillary first tank side portion,
The BOG pipe of the second reliquefaction apparatus is connected to the BOG capillary second tank side portion,
The RLG piping of the first reliquefaction apparatus is connected to the RLG capillary first tank side portion,
The RLG piping of the second reliquefaction apparatus is connected to the RLG mother pipe second tank side portion. A plurality of tanks storing flammable liquefied gas;
A plurality of reliquefaction apparatuses for reliquefying the boil off gas of the liquefied gas,
With BOG capillary,
A valve or spool piece group formed in the BOG capillary such that the BOG capillary is divided into a plurality of BOG capillary portions;
RLG capillary,
A group of valve or spool pieces formed in the RLG capillary such that the RLG capillary is divided into a plurality of RLG capillary portions;
A plurality of tank side BOG pipes each connecting the plurality of tanks to the plurality of BOG capillary portions;
A plurality of tank-side RLG piping for connecting the plurality of tanks to the plurality of RLG mother pipe portions, respectively,
Each of the plurality of reliquefaction devices
A compressor for compressing the boil-off gas
An explosion-proof motor for driving the compressor,
A valve or spool piece is formed in each of the plurality of tank side BOG pipes,
A valve or spool piece is formed in each of the plurality of tank side RLG pipes,
Each of the plurality of reliquefaction apparatus,
BOG piping for the reliquefaction apparatus side for supplying the boil off gas to the compressor;
A reliquefaction apparatus side RLG piping for reverting the reliquefaction gas in which the boil off gas is reliquefied;
The plurality of reliquefaction apparatuses are respectively connected to the plurality of BOG capillary portions via the reliquefaction apparatus side BOG piping,
And the plurality of reliquefaction apparatuses are respectively connected to the plurality of RLG mother pipe portions via the reliquefaction apparatus-side RLG piping. 11. The method according to any one of claims 8 to 10,
And the plurality of reliquefaction devices are each equipped with the plurality of tanks. 11. The method according to any one of claims 8 to 10,
Each of the plurality of reliquefaction apparatuses includes a motor covered with an explosion-proof box in place of the explosion-proof motor. The method of claim 8,
Each of the plurality of reliquefaction apparatuses and the preliminary reliquefaction apparatus include a motor covered with an explosion-proof box in place of the explosion-proof motor. delete delete delete delete

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