KR102296311B1 - Gas Treatment System, Vessel having the Gas Treatment System and FSRU Vessel having the Gas Treatment System - Google Patents

Abstract

A gas processing system according to an embodiment of the present invention includes: a liquefied gas supply line connecting a liquefied gas storage tank and a customer; a suction device provided on the liquefied gas supply line and sucking boil-off gas generated from the liquefied gas storage tank through the liquefied gas supplied from the liquefied gas storage tank; and a recondenser provided on the liquefied gas supply line and recondensing the mixed gas discharged from the suction device through the liquefied gas supplied from the liquefied gas storage tank.

Description

A gas treatment system, a ship including a gas treatment system, and an offshore floating structure including a gas treatment system

The present invention relates to a gas treatment system, a ship comprising the gas treatment system, and an offshore floating structure comprising the gas treatment system.

According to recent technology development, liquefied gas such as liquefied natural gas (Liquefied Natural Gas) and liquefied petroleum gas (Liquefied Petroleum Gas) is widely used to replace gasoline or diesel.

Liquefied natural gas is liquefied by cooling and liquefying methane obtained by refining natural gas collected from a gas field. It is a colorless and transparent liquid with few pollutants and high calorific value. On the other hand, liquefied petroleum gas is a fuel made into a liquid by compressing the gas containing propane (C3H8) and butane (C4H10) together with petroleum from oil fields at room temperature. Liquefied petroleum gas, like liquefied natural gas, is colorless and odorless and is widely used as fuel for household, business, industrial, and automobile use.

Such liquefied gas is stored in a liquefied gas storage tank installed on the ground or stored in a liquefied gas storage tank provided in a ship that is a means of transportation to navigate the ocean. The volume of liquefied petroleum gas is reduced to 1/260 of propane and 1/230 of butane by liquefaction, which has the advantage of high storage efficiency.

Such liquefied gas is supplied and used by various sources of demand. Recently, an LNG fuel supply method in which LNG is used as a fuel in an LNG carrier that transports liquefied natural gas to drive an engine has been developed. The method used is being applied to ships other than LNG carriers and FSRUs.

The present invention was created to improve the prior art, and an object of the present invention is to include a gas processing system capable of efficiently processing boil-off gas generated during bunkering of liquefied gas in a liquefied gas propulsion vessel, a gas processing system It is intended to provide an offshore floating structure comprising a ship and a gas treatment system.

In addition, in addition to the above object, an object of the present invention is a gas processing system that can implement efficient processing of liquefied gas or boil-off gas in a liquefied gas propulsion vessel, a ship including a gas processing system, and an offshore floating type including a gas processing system to provide a structure.

A gas processing system according to an embodiment of the present invention includes: a liquefied gas supply line connecting a liquefied gas storage tank and a customer; a suction device provided on the liquefied gas supply line and sucking boil-off gas generated from the liquefied gas storage tank through the liquefied gas supplied from the liquefied gas storage tank; and a recondenser provided on the liquefied gas supply line and recondensing the mixed gas discharged from the suction device through the liquefied gas supplied from the liquefied gas storage tank.

Specifically, it is provided on the downstream side of the re-condenser on the liquefied gas supply line, further comprising a pump for pressurizing the liquefied gas supplied from the re-condenser, wherein the re-condenser liquefies the mixed gas discharged from the suction device. By completely recondensing the liquefied gas supplied from the gas storage tank and supplying it to the pump, the effective suction head of the pump can be satisfied without a separate buffer tank.

Specifically, it further comprises a liquefied gas return line branched between the recondenser and the pump on the liquefied gas supply line and connected to the liquefied gas storage tank, the liquefied gas return line, the ash discharged from the recondenser When the condensed gas is not completely re-condensed, the re-condensed gas discharged from the re-condenser may be returned to the liquefied gas storage tank.

Specifically, the pump is a high pressure pump, is provided upstream of the suction device on the liquefied gas supply line, the feeding pump for supplying the liquefied gas stored in the liquefied gas storage tank to the suction device; and a vaporizer provided downstream of the high-pressure pump on the liquefied gas supply line to vaporize the liquefied gas supplied from the high-pressure pump.

Specifically, the suction device may be an ejector.

Specifically, the recondenser may be a pipe type recondenser (Inline type recondenser).

Specifically, it may further include a BOG-ejector suction line connecting the suction device and the liquefied gas storage tank and supplying BOG generated in the liquefied gas storage tank to the suction device.

Specifically, it may be a ship characterized in that it includes the gas treatment system.

Specifically, it may be a floating offshore structure comprising the gas processing system.

The gas treatment system according to the present invention can efficiently process BOG generated and returned during bunkering, thereby preventing wastage of BOG.

In addition, the gas treatment system according to the present invention has an effect of preventing the internal pressure of the liquefied gas storage tank of the bunkering vessel from rising during bunkering.

In addition, the gas treatment system according to the present invention has the effect of having a pipe-type recondenser to sufficiently secure the construction space of the gas treatment system and prevent unnecessary waste of boil-off gas, and energy consumption of the reliquefaction apparatus has the effect of reducing

In addition, the gas treatment system according to the present invention includes a buffer tank upstream of the high-pressure pump (boosting pump) to ensure a stable liquefied gas inflow pressure into the high-pressure pump (boosting pump), thereby increasing the stability of the gas treatment system there is

In addition, the gas treatment system according to the present invention controls the flow rate of boil-off gas flowing into the pipe-type recondenser through the state of the liquefied gas flowing into the high-pressure pump (boosting pump), so that the Even if a buffer tank is not provided, a stable liquefied gas inlet pressure to the high-pressure pump (boosting pump) can be stably secured, the construction space can be optimized, and the operation of the BOG compressor can be reduced, thereby reducing power consumption. there is an effect

In addition, in the gas treatment system according to the present invention, a pipe-type recondenser is installed downstream of the reliquefaction apparatus, and a branch line connected to the pipe type recondenser by bypassing the reliquefaction apparatus is installed to consume energy of the reliquefaction apparatus has the effect of reducing

In addition, the gas treatment system according to the present invention further includes an LP compressor that compresses and supplies BOG with a pipe type recondenser in addition to the HP BOG compressor that compresses and supplies BOG to a reliquefaction device for reliquefying BOG. Accordingly, it is possible to reduce the energy of the reliquefaction apparatus and at the same time reduce the net energy consumption of the BOG compressor.

In addition, the gas treatment system according to the present invention is further provided with a condensing tank for storing excess liquefied gas downstream of the pipe-type recondenser, so that the energy of the ship can be used efficiently, and the thermal load of the liquefied gas storage tank can be reduced. can have an effect.

1 is a conceptual diagram illustrating a bunkering of a ship having a gas processing system according to an embodiment of the present invention.
2 is a conceptual diagram of a gas processing system according to a first embodiment of the present invention.
3 is a conceptual diagram of a ship equipped with a gas processing system according to an embodiment of the present invention.
4 is a conceptual diagram of a gas processing system according to a second embodiment of the present invention.
5 is a conceptual diagram of a gas processing system according to a third embodiment of the present invention.
6 is a conceptual diagram of a gas processing system according to a fourth embodiment of the present invention.
7 is a conceptual diagram of a gas processing system according to a fifth embodiment of the present invention.

The objects, specific advantages and novel features of the present invention will become more apparent from the following detailed description and preferred embodiments taken in conjunction with the accompanying drawings. In the present specification, in adding reference numbers to the components of each drawing, it should be noted that only the same components are given the same number as possible even though they are indicated on different drawings. In addition, in describing the present invention, if it is determined that a detailed description of a related known technology may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

Hereinafter, in this specification, liquefied gas may be used to encompass all gas fuels that are generally stored in a liquid state, such as LNG or LPG, ethane, ethylene, ammonia, etc. Also, a case that is not in a liquid state by heating or pressurization may be expressed as a liquefied gas for convenience. This can be applied to boil-off gas as well.

In addition, for convenience, LNG can be used to encompass both NG (Natural Gas) in a liquid state as well as NG in a supercritical state. It can be used in the meaning of including liquefied boil-off gas as well as boil-off gas of.

Liquefied gas may be referred to regardless of a change in state, such as a liquid state, a gaseous state, a liquid and gas mixture state, a supercooled state, a supercritical state, and the like, and it should be noted that boil-off gas is also the same. In addition, it is obvious that the subject of the present invention is not limited to liquefied gas, but may be a liquefied gas processing system and/or a boil-off gas processing system, and the systems in the drawings to be described below may be applied to each other.

In addition, the embodiments of the gas processing systems 100 to 500 of the present invention may be configured in combination with each other, and of course, addition of each configuration may be made to cross each other. And the gas processing systems 100 to 500 according to the embodiment of the present invention may be mounted on a hull (not shown).

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a conceptual diagram illustrating a bunkering of a ship having a gas processing system according to an embodiment of the present invention, and FIG. 2 is a conceptual diagram of a gas processing system according to a first embodiment of the present invention.

1 and 2, the gas processing system 100 according to the embodiment of the present invention includes a liquefied gas storage tank 10 for unloading, a pump 20 for loading and unloading, and a pump 21 for fuel supply. , a vaporizer 30 , a pipe-type recondenser 40 , a boil-off gas compressor 50 , a propulsion engine 60 , and a liquefied gas storage tank 70 for shipment.

In this case, the vessel 1 according to the present invention may be a bunkering vessel 1 , and the vessel 2 supplied with liquefied gas by the bunkering vessel 1 may be an LNG-propelled vessel 2 . In addition, the vessel 2 supplied with liquefied gas by the bunkering vessel 1 is not necessarily limited to the LNG propulsion vessel 2 and may correspond to any vessel having an LNG storage tank, such as an LNG carrier. am.

Hereinafter, a gas processing system 100 according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2 .

Before describing the gas processing system 100 according to the present invention, the liquefied gas unloading operation (bunkering) of the vessel 1 including the gas processing system 100 of the present invention shown in FIG. 1 will be described. .

Referring to FIG. 1 , the bunkering vessel 1 uses the liquefied gas stored in the liquefied gas storage tank 10 for loading and unloading, and the liquefied gas storage tank 70 for loading of the LNG propulsion vessel 2 through the pump 20 for loading and unloading. supply to

The liquefied gas stored in the liquefied gas storage tank 10 for unloading is supplied to the liquefied gas storage tank 70 for shipment through the bunkering line L1 after processing in the gas processing system 100, and transport and shipment of the liquefied gas BOG generated in the liquefied gas storage tank 70 for shipping generated by ) and may be supplied to the propulsion engine 60 or the liquefied gas storage tank 10 for unloading after processing.

The bunkering vessel 1 is propelled through a propulsion engine 60 using liquefied gas stored in a liquefied gas storage tank 10 for unloading as fuel, and the propulsion engine 60 is processed in the gas treatment system 100 . The liquefied gas or boil-off gas can be consumed by being supplied through the liquefied gas supply line (L3). At this time, the propulsion engine 60 may also be called a demand for propulsion.

The LNG propulsion vessel 2 is propelled through a propulsion engine 83 using liquefied gas stored in a liquefied gas storage tank 80 for propulsion as fuel, and the propulsion engine 83 is a liquefied gas storage tank for propulsion ( 80) and consumes the supplied liquefied gas. The liquefied gas stored in the liquefied gas storage tank 80 for propulsion is pressurized by the fuel supply pump 81 and high-pressure gasified in the fuel processing system 82, and then through a supply line (not shown) to the propulsion engine. (83) is supplied.

In the above description, the liquefied gas storage tank of the LNG propulsion vessel (2) is separated into a liquefied gas storage tank (70) for shipping and a liquefied gas storage tank (80) for propulsion, but this is not limited, and the propulsion engine (83) The liquefied gas or boil-off gas stored in the liquefied gas storage tank 70 for shipping, not the liquefied gas storage tank 80 for propulsion, can be used as fuel, and the bunkering vessel 1 is a liquefied gas storage tank for shipping 70 ) as well as the liquefied gas storage tank 80 for propulsion can be loaded with liquefied gas, of course.

Hereinafter, with reference to FIG. 2 , the gas processing system 100 for performing the liquefied gas unloading operation (bunkering) of the above-described bunkering vessel 1 will be described in detail.

Before describing the individual components of the gas processing system 100 according to the embodiment of the present invention, basic flow paths that organically connect the individual components will be described. Here, the flow path is a passage through which the fluid flows and may be a line.

In the embodiment of the present invention, a bunkering line (L1), a boil-off gas return line (L2), a boil-off gas liquefaction line (L2a), a boil-off gas branch line (L2b), a boil-off gas consumer supply line (L2c), a liquefied gas supply line ( L3) and the boil-off gas supply line (L5) may be further included. Valves (not shown) capable of adjusting the opening degree may be installed in each line, and the supply amount of boil-off gas or liquefied gas may be controlled according to the adjustment of the opening degree of each valve.

The bunkering line L1 connects the liquefied gas storage tank 10 for unloading and the liquefied gas storage tank 70 for loading, and includes a pump 20 for loading and unloading through the pump 20 for loading and unloading. The liquefied gas stored in the gas storage tank 10 may be supplied to the liquefied gas storage tank 70 for shipment. Here, the bunkering line L1 may include a pipe-type recondenser 40 downstream of the unloading pump 20 .

The boil-off gas return line (L2) connects the liquefied gas storage tank 70 for shipment and the propulsion engine 60; It is possible to recover the return boil-off gas generated in the evaporator, compress it with the boil-off gas compressor 50 and then supply it to the propulsion engine 60 .

At this time, the boil-off gas return line (L2) may include a buffer tank (B1) and a buffer tank (B2) at each downstream and upstream of the boil-off gas compressor (50), and the liquefied gas supply line (L3) and liquefaction for unloading A boil-off gas supply line L5 for supplying boil-off gas generated in the gas storage tank 10 may be connected.

In addition, the boil-off gas return line (L2) may be connected to a liquefied gas supply line (L3) and a boil-off gas supply line (L5) upstream of the boil-off gas compressor 50, specifically, the boil-off gas supply line (L5) may be connected to the downstream of the vaporizer 30 on the liquefied gas supply line (L3).

Here, the boil-off gas return line (L2) is branched between the downstream of the boil-off gas compressor (50) and the buffer tank (B1) and is connected to the liquefied gas storage tank (10) for unloading, and having a pipe-type recondenser (40) BOG branch line (L2a), BOG branch line (L2b) branched from upstream of pipe-type recondenser 40 on BOG branch line (L2a) and connected downstream, BOG branching line (L2b) and buffer tank (B1) downstream It may further include a boil-off gas consumer supply line (L2c) connecting the consumer 61 .

The liquefied gas supply line (L3) connects the liquefied gas storage tank 10 for unloading and the upstream of the buffer tank B2, and includes a fuel supply pump 21 and a vaporizer 30 to store liquefied gas for unloading The liquefied gas stored in the tank 10 may be supplied to the propulsion engine 60 .

The boil-off gas supply line (L5) connects the liquefied gas storage tank 10 for unloading and the upstream of the buffer tank B2, and uses the boil-off gas generated from the liquefied gas storage tank 10 for unloading into the propulsion engine 60. can be supplied with

Hereinafter, individual components that are organically formed by each of the above-described lines L1 to L3 to implement the gas processing system 100 will be described.

The liquefied gas storage tank 10 for unloading stores liquefied gas to be supplied to the liquefied gas storage tank 70 for shipping. The liquefied gas storage tank 10 for unloading should store the liquefied gas in a liquid state. At this time, the liquefied gas storage tank 10 may have a pressure tank shape.

Here, the liquefied gas storage tank 10 for unloading is disposed inside the hull, and may be formed in four, for example, in front of the engine room (signs not shown).

In addition, the liquefied gas storage tank 10 for unloading may be an independent storage tank that withstands a pressure of 5 to 10 bar (preferably 7 to 8 bar).

Due to this, it is possible to accommodate at least a part of the return BOG generated when the liquefied gas is shipped to the liquefied gas storage tank 70 for shipping, so that it is possible to efficiently process the return BOG, and the liquefied gas for unloading separately during bunkering Since there is no need to introduce gas for pressurization into the storage tank 10, there is an effect that the bunkering driving cost is reduced.

The unloading pump 20 is provided on the bunkering line L1, is installed inside or outside the unloading liquefied gas storage tank 10, and is for loading the liquefied gas stored in the unloading liquefied gas storage tank 10 It can be supplied to the liquefied gas storage tank (70).

Here, the unloading pump 20 may pressurize the liquefied gas discharged from the unloading liquefied gas storage tank 10 to slightly increase the pressure and temperature, and the pressurized liquefied gas may still be in a liquid state.

At this time, the unloading pump 20 may be a submersible pump when it is provided inside the liquefied gas storage tank 10 for loading and unloading, and when it is installed outside the liquefied gas storage tank 10 for loading and unloading, the liquefied gas for loading and unloading It may be provided at a position inside the hull lower than the water level of the liquefied gas stored in the storage tank 10 and may be a centrifugal pump.

The fuel supply pump 21 is provided on the liquefied gas supply line L3, is installed inside or outside the liquefied gas storage tank 10 for unloading, and is stored in the liquefied gas storage tank 10 for unloading. may be supplied to the vaporizer 30 .

Specifically, the fuel supply pump 21 is provided between the liquefied gas storage tank 10 for unloading and the vaporizer 30 on the liquefied gas supply line L3 and stored in the liquefied gas storage tank 10 for unloading. The liquefied gas may be supplied to the vaporizer 30 by pressurizing it.

The fuel supply pump 21 may pressurize the liquefied gas stored in the liquefied gas storage tank 10 for unloading to 5 to 20 bar and supply it to the carburetor 30 . Of course, the fuel supply pump 21, the pressurization pressure is not limited to 5 to 20 bar and may be variable according to the required pressure of the carburetor 30. Here, the fuel supply pump 21 is a liquefied gas storage tank for unloading. By pressurizing the liquefied gas discharged from (10), the pressure and temperature may be somewhat increased, and the pressurized liquefied gas may still be in a liquid state.

In this case, the fuel supply pump 21 may be a submersible pump when provided inside the liquefied gas storage tank 10 for unloading, and liquefaction for unloading when installed outside the liquefied gas storage tank 10 for unloading. It may be provided at a position inside the hull lower than the level of the liquefied gas stored in the gas storage tank 10 and may be a centrifugal pump.

The vaporizer 30 may be connected to the liquefied gas supply line L3 to vaporize the liquefied gas discharged from the fuel supply pump 21 and then supply it to the boil-off gas compressor 50 . In this case, a buffer tank B2 is provided upstream of the boil-off gas compressor 50 , and the liquefied gas forcedly vaporized in the vaporizer 30 may be temporarily stored.

Specifically, the vaporizer 30 may be connected to an upstream of the boil-off gas compressor 60 on the boil-off gas return line L2 and the liquefied gas supply line L3, and 5 to 5 discharged from the fuel supply pump 21 After vaporizing the liquefied gas having a pressure of 20 bar, the vaporized liquefied gas may be supplied to the boil-off gas compressor 50 .

The vaporizer 30 may vaporize liquefied gas through a separate seawater supply line (not shown) in the case of a direct vaporization method, and an intermediate heat medium heat exchanger (not shown) and an intermediate heat medium circulation line in the case of an indirect vaporization method (not shown) may be connected through an intermediate heating medium to be supplied and heat exchange with the liquefied gas to vaporize the liquefied gas.

The pipe-type recondenser 40 heats the liquefied gas supplied from the bunkering line L1 and the boil-off gas supplied from the boil-off gas return line L2 to recondensate the boil-off gas.

The pipe-type recondenser 40 heats the boil-off gas with liquefied gas to re-condense it and then supplies it to the liquefied gas storage tank 10 for unloading, so that the boil-off gas is re-introduced into the liquefied gas storage tank 10 for unloading. Drop the temperature of the, thereby suppressing the increase in the internal pressure of the liquefied gas storage tank (10) for unloading.

In addition, the pipe-type recondenser 40 heats the liquefied gas with the boil-off gas and supplies it to the liquefied gas storage tank 70 for shipping, thereby increasing the temperature of the liquefied gas supplied to the liquefied gas storage tank 70 for shipping. There is an effect of being able to properly supply the liquefied gas to the temperature required by the liquefied gas storage tank 70 for shipment accordingly.

Existing recondensers are arranged upstream of a high-pressure pump on a liquefied gas processing system, and then receive boil-off gas and liquefied gas to re-condense the boil-off gas to a low temperature of liquefied gas. In this system, conventional recondensers are manufactured in the form of containers to match the net positive suction head (NPSH) of the high-pressure pump and increase the heat exchange surface area. There were downsides. In addition, there is a disadvantage that a complex control program must be designed for the water level control of the recondenser and the internal pressure of the recondenser, and there is a problem in that excessive costs are added accordingly.

Accordingly, in the embodiment of the present invention, all of the above problems are solved by manufacturing the recondenser as an in-line pipe type.

That is, the pipe type recondenser 40 according to the embodiment of the present invention is manufactured as an in-line pipe type, a nozzle (not shown) is formed, and due to the configuration of the nozzle, the pipe type recondenser 40 ) is converted to boil-off gas (BOG) supplied to fine bubbles, and these fine bubbles are immediately re-condensed.

Through this effect, the pipe-type recondenser 40 does not need to be manufactured in the form of a container in order to increase the heat exchange surface area, and thus the space can be minimized.

In addition, the pipe-type recondenser 40 does not require a control system, and thus has the effect of minimizing the risk by simplifying the control system, and has a very simple configuration, so that CAPEX can be reduced, and the space in the hull can be secured to the maximum. there are advantages to

In the embodiment of the present invention, a control unit (not shown) for controlling the flow rate of the boil-off gas flowing on the boil-off gas branch line L2b by measuring the temperature of the liquefied gas or boil-off gas discharged from the pipe-type recondenser 40 ) may be further included.

Accordingly, in the embodiment of the present invention, a temperature sensor (not shown) for measuring the temperature of liquefied gas or BOG discharged from the pipe-type recondenser 40 and BOG flowing on the BOG branch line L2b It may further include a control valve (V) for controlling the flow rate, the control unit may be configured to be connected to the temperature sensor and the control valve (V) in a wired or wireless connection to control.

The control unit stores the liquefied gas for shipment in the pipe-type recondenser 40 so that the temperature of the boil-off gas supplied from the pipe-type recondenser 40 to the unloading liquefied gas storage tank 10 exceeds a preset boil-off gas temperature or in the pipe-type recondenser 40 The boil-off gas branch line L2b may be controlled so that the temperature of the liquefied gas supplied to the tank 70 is less than a preset liquefied gas temperature.

Specifically, when the temperature of the boil-off gas supplied from the pipe-type recondenser 40 to the liquefied gas storage tank 10 for unloading is less than or equal to the preset boil-off gas temperature, the control valve V is opened to open, Controls the BOG supplied to the pipe-type recondenser 40 through the BOG return line (L2) to bypass the pipe-type recondenser 40 through the BOG branch line (L2b), and the pipe-type recondenser ( 40), when the temperature of the liquefied gas supplied to the liquefied gas storage tank 70 for shipment is higher than the preset liquefied gas temperature, the opening of the control valve (V) is closed and the pipe type material is passed through the boil-off gas return line (L2). The boil-off gas supplied to the condenser 40 may be controlled to be supplied to the pipe-type recondenser 40 .

As described above, the gas treatment system 100 according to the present invention can efficiently process the BOG generated during bunkering, thereby preventing wastage of BOG, and liquefied gas of the bunkering vessel 1 during bunkering. There is an effect that can prevent the internal pressure of the storage tank 10 from rising.

In addition, the gas treatment system 100 according to the present invention includes a pipe-type recondenser 40 to sufficiently secure a space for constructing the gas treatment system 100 and prevent unnecessary waste of boil-off gas. There is an effect that can reduce the energy consumption of the reliquefaction device.

The BOG compressor 50 is provided on the BOG return line L2, and compresses the liquefied gas or BOG supplied from the liquefied gas storage tank 10 for unloading, or a liquefied gas storage tank 70 for shipment. Compresses the return boil-off gas generated from

The BOG compressor 50 receives BOG or liquefied gas stored in the liquefied gas storage tank 10 for unloading, compresses it, and supplies it to the propulsion engine 60 or the BOG consumer 61, or liquefied gas for shipment. The return BOG generated from the storage tank 70 can be compressed and supplied to the propulsion engine 60 or the BOG consumer 61 .

Specifically, the BOG compressor 50 receives and compresses the liquefied gas stored in the liquefied gas storage tank 10 for unloading through the liquefied gas supply line L3, or generated in the liquefied gas storage tank 10 for unloading. The evaporated BOG may be supplied through the BOG supply line L5 and compressed, and the return BOG generated and returned from the liquefied gas storage tank 70 for shipment may be compressed.

The BOG compressor 50 may supply the compressed BOG to the propulsion engine 60 through the BOG return line L2, or to the BOG consumer 61 through the BOG supply line L2c. Alternatively, it may be supplied to the liquefied gas storage tank 10 for unloading through the boil-off gas liquefaction line L2a.

The boil-off gas compressor 50 can be compressed to 5 to 20 bar when supplied to the propulsion engine 60 or the boil-off gas consumer 61, and compressed to 5 to 10 bar when supplied to the liquefied gas storage tank 10 for unloading. can do.

The propulsion engine 60 supplies thrust to the bunkering vessel 1 by using the liquefied gas or boil-off gas stored in the liquefied gas storage tank 10 for unloading as a fuel.

In the propulsion engine 60, as the piston (not shown) inside the cylinder (not shown) reciprocates by combustion of liquefied gas, boil-off gas, or oil, the crankshaft (not shown) connected to the piston is A shaft (not shown) that is rotated and connected to the crankshaft may be rotated. Accordingly, the propulsion engine 60, as the propeller (not shown) connected to the shaft rotates during driving, the bunkering vessel 1 may move forward or backward.

In an embodiment of the present invention, the propulsion engine 60 may be a dual fuel engine (DFDE), but is not limited thereto, and may be a high-pressure gas injection engine (MEGI) or a low-speed two-stroke low-pressure gas injection engine (XDF). That is, the type of the propulsion engine 60 is not particularly limited.

The boil-off gas consumer 61 is branched from the downstream of the buffer tank B1 on the boil-off gas return line L2 and is connected to the boil-off gas consumer supply line L2c, and the liquefied gas storage tank 10 for unloading or liquefaction for shipment BOG generated in the gas storage tank 70 may be consumed.

The boil-off gas consumer 61 may be, for example, a gas combustion unit (GCU), a boiler, or an engine for power generation (DFDG), but is not limited thereto, and any device capable of consuming the boil-off gas may be possible.

The liquefied gas storage tank 70 for shipping stores the liquefied gas to be transported. The liquefied gas storage tank 70 for shipping should store the liquefied gas in a liquid state. At this time, the liquefied gas storage tank 70 for shipping may have a pressure tank shape.

Here, the liquefied gas storage tanks 70 for shipping are provided inside the LNG-propelled vessel 2 and may be formed, for example, in three or four in front of the engine room (not shown). In addition, the liquefied gas storage tank 70 for shipping is, for example, a membrane type tank, but is not limited thereto, and the type is not particularly limited to various types, such as an independent tank.

The buffer tank B1 is disposed between the BOG compressor 50 and the propulsion engine 60 on the BOG return line L2, and stores BOG to be supplied to the propulsion engine 60 or the BOG consumer 61. Can be temporarily stored.

Through this, the buffer tank B1 can supply BOG at a stable pressure, temperature or flow rate to the propulsion engine 60 or the BOG consumer 61 , thereby increasing the efficiency of the propulsion engine 60 or the BOG consumer 61 . This has an increasing effect.

The buffer tank B2 is disposed downstream of the BOG compressor 50 on the BOG return line L2 , and may temporarily store the BOG to be supplied to the BOG compressor 50 .

Also, the buffer tank B2 is connected to the liquefied gas supply line L3 and the boil-off gas supply line L5 to temporarily store the liquefied gas or boil-off gas stored in the liquefied gas storage tank 10 for unloading.

Through this, the buffer tank B2 can supply BOG at a stable pressure or temperature to the BOG compressor 50 , thereby increasing the efficiency of the BOG compressor 50 .

3 is a conceptual diagram of a ship equipped with a gas processing system according to an embodiment of the present invention, and FIG. 4 is a conceptual diagram of a gas processing system according to a second embodiment of the present invention.

3 and 4, the gas processing system 200 according to the embodiment of the present invention is a liquefied gas storage tank (T), a feeding pump (P), a propulsion engine (E), a pipe type recondenser 210 , a buffer tank 220 , a boosting pump 230 , a vaporizer 240 , and a boil-off gas compressor 250 .

In this case, the vessel 3 according to the present invention may correspond to any vessel having an LNG storage tank, such as an LNG propulsion vessel, an LNG carrier, a FSRU, and the like.

Hereinafter, a gas processing system 200 according to an embodiment of the present invention will be described with reference to FIGS. 3 and 4 .

Before describing the individual components of the gas processing system 200 according to the embodiment of the present invention, basic flow paths that organically connect the individual components will be described. Here, the flow path is a passage through which the fluid flows and may be a line.

In an embodiment of the present invention, the liquefied gas supply line (L4) may further include a liquefied gas return line (L4a) and a boil-off gas supply line (L5). Valves (not shown) capable of adjusting the opening degree may be installed in each line, and the supply amount of boil-off gas or liquefied gas may be controlled according to the adjustment of the opening degree of each valve.

The liquefied gas supply line (L4) connects the liquefied gas storage tank (T) and the propulsion engine (E), and includes a feeding pump (P), a pipe type recondenser (210), a buffer tank (220), and a high pressure pump (230). ) and a vaporizer 240 can be provided to supply the liquefied gas stored in the liquefied gas storage tank (T) to the propulsion engine (E).

Here, the liquefied gas supply line L4 may include a liquefied gas return line L4a branched between the pipe-type recondenser 210 and the buffer tank 220 and connected to the liquefied gas storage tank T. . A detailed configuration of the liquefied gas return line L4a will be described later.

The boil-off gas supply line (L5) connects the liquefied gas storage tank (T) and the pipe-type recondenser (210), and the boil-off gas generated in the liquefied gas storage tank (T) is supplied to the pipe-type recondenser (210). can

Hereinafter, individual components that are organically formed by each of the above-described lines L4 to L5 to implement the gas processing system 200 will be described.

In the embodiment of the present invention, the configuration of the liquefied gas storage tank (T), the feeding pump (P), the propulsion engine (E), and the carburetor 240 in the gas processing system 100 according to the first embodiment of the present invention It is the same as the configuration of the liquefied gas storage tank 70 for shipping, the fuel supply pump 21, the propulsion engine 60, and the carburetor 30, so it should be replaced.

The pipe-type recondenser 210 is provided on the liquefied gas supply line L4 and recondenses the boil-off gas generated in the liquefied gas storage tank T through the liquefied gas stored in the liquefied gas storage tank T. .

Specifically, the pipe type recondenser 210 is provided between the feeding pump P on the liquefied gas supply line L4 and the buffer tank 220, and the liquefied gas storage tank ( The boil-off gas of T) may be supplied, and the boil-off gas may be re-condensed by receiving the liquefied gas of the liquefied gas storage tank T through the liquefied gas supply line L4.

In an embodiment of the present invention, the liquefied gas return line L4a liquefies at least a portion of the liquefied gas supplied from the pipe-type recondenser 210 when the internal pressure of the buffer tank 220 is greater than or equal to the preset tank pressure. It can be returned to the gas storage tank (T).

At this time, a control valve V may be provided on the liquefied gas return line L4a. The control valve V opens the opening when the internal pressure of the buffer tank 220 is less than the preset buffer tank pressure. , to return at least a portion of the liquefied gas supplied from the pipe-type recondenser 210 to the liquefied gas storage tank T, and when the internal pressure of the buffer tank 220 becomes greater than or equal to the preset tank pressure, the opening is closed Thus, all of the liquefied gas supplied from the pipe-type recondenser 210 may be supplied to the buffer tank 220 .

Through this, the gas treatment system 200 according to the embodiment of the present invention can effectively manage the internal pressure of the buffer tank 220 , so that a separate device for adjusting the pressure of the buffer tank 220 is not required. It has the effect of reducing costs.

The buffer tank 220 may temporarily store the liquefied gas supplied from the pipe-type recondenser 210 , and then supply the liquefied gas to the high-pressure pump 230 .

Specifically, the buffer tank 220 is provided between the pipe-type recondenser 210 and the high-pressure pump 230 on the liquefied gas supply line L4, and is temporarily supplied with liquefied gas from the pipe-type recondenser 210. After storage, the liquefied gas having a flow rate that satisfies the effective suction head (NPSH) of the high-pressure pump 230 may be supplied to the high-pressure pump 230 .

As described above, in the gas treatment system 200 according to the present invention, a buffer tank 220 is provided upstream of the high-pressure pump 230 to ensure a stable liquefied gas inlet pressure and flow rate into the high-pressure pump 230 . (200) has the effect of increasing the stability.

The high-pressure pump 230 is provided on the liquefied gas supply line L4 and may pressurize the liquefied gas supplied from the feeding pump P to a high pressure.

At this time, the high-pressure pump 230 may pressurize the liquefied gas according to the pressure required by the propulsion engine (E).

The boil-off gas compressor 250 is provided on the boil-off gas supply line L5, compresses the boil-off gas generated in the liquefied gas storage tank T, and supplies it to the pipe-type recondenser 210 . Here, the BOG compressor 250 may be controlled to supply BOG with a fixed capacity or a variable capacity.

The boil-off gas compressor 250, when the internal pressure of the liquefied gas storage tank T is greater than or equal to the preset internal pressure, compresses the boil-off gas and supplies it to the pipe type recondenser 210, and the liquefied gas storage tank T When the internal pressure of is less than the preset internal pressure, the boil-off gas may not be compressed so that the boil-off gas generated in the liquefied gas storage tank (T) is compressed in the liquefied gas storage tank (T).

Through this, the gas treatment system 200 according to the embodiment of the present invention can effectively manage the internal pressure of the liquefied gas storage tank T, thereby improving safety and reducing the waste of boil-off gas. .

5 is a conceptual diagram of a gas processing system according to a third embodiment of the present invention.

5, the gas treatment system 300 according to the embodiment of the present invention is a liquefied gas storage tank (T), a feeding pump (P), a propulsion engine (E), a pipe type recondenser (310) , a high pressure pump 320 , a vaporizer 330 , a first BOG compressor 341 , a second BOG compressor 342 , and a control unit 360 .

Hereinafter, a gas processing system 300 according to an embodiment of the present invention will be described with reference to FIG. 5 .

Before describing the individual components of the gas processing system 300 according to the embodiment of the present invention, basic flow paths that organically connect the individual components will be described. Here, the flow path is a passage through which the fluid flows and may be a line.

In the embodiment of the present invention, it may further include a liquefied gas supply line (L4), a boil-off gas supply line (L5), boil-off gas-recondenser supply line (L5a), the boil-off gas consumer supply line (L5b). Valves (not shown) capable of adjusting the opening degree may be installed in each line, and the supply amount of boil-off gas or liquefied gas may be controlled according to the adjustment of the opening degree of each valve.

The liquefied gas supply line (L4) connects the liquefied gas storage tank (T) and the propulsion engine (E), and a feeding pump (P), a pipe type recondenser (310), a high pressure pump (320) and a vaporizer (330) By having a liquefied gas stored in the liquefied gas storage tank (T) can be supplied to the propulsion engine (E).

The boil-off gas supply line (L5) connects the liquefied gas storage tank (T) and the propulsion engine (E) and includes first and second boil-off gas compressors (341 and 342), the liquefied gas storage tank (T) generated from BOG may be supplied to the propulsion engine (E).

Here, the boil-off gas supply line L5 is branched between the first boil-off gas compressor 341 and the second boil-off gas compressor 342 and is connected to the pipe-type recondenser 310 - the boil-off gas-recondenser supply line L5a ) and branched between the first boil-off gas compressor 341 and the second boil-off gas compressor 342 and further include a boil-off gas consumer supply line (L5b) connected to the power generation engine 351 and the gas combustion device 352. can

Hereinafter, individual components that are organically formed by each of the above-described lines L4 to L5 to implement the gas processing system 300 will be described.

In an embodiment of the present invention, the configuration of the liquefied gas storage tank (T), the feeding pump (P), the propulsion engine (E), the high-pressure pump 320 and the carburetor 330 is a gas according to the first embodiment of the present invention The configuration of the liquefied gas storage tank 70 for shipping, the pump 21 for fuel supply, the propulsion engine 60 and the carburetor 30 in the processing system 100 and the gas processing system according to the second embodiment of the present invention Since it is the same as the configuration of the high-pressure pump 230 in 200, it should be replaced.

The pipe type recondenser 310 is provided without a separate buffer tank between the feeding pump P and the high pressure pump 320 on the liquefied gas supply line L4, and the boil-off gas supplied from the liquefied gas storage tank T is recondensed through the liquefied gas supplied from the liquefied gas storage tank (T).

The controller 360 controls the flow rate of boil-off gas supplied to the pipe-type recondenser 310 to satisfy the effective suction head (NPSH) of the high-pressure pump 32 .

Accordingly, in the embodiment of the present invention, the boil-off gas-recondenser supply line (L5a) provided on the control valve 361 for controlling the flow rate of the boil-off gas flowing on the boil-off gas-recondenser supply line (L5a), liquefaction It is provided upstream of the high-pressure pump 320 on the gas supply line (L4) and measures the physical properties of the liquefied gas or boil-off gas flowing into the high-pressure pump 320 (a flow sensor 362 for measuring the flow rate), the pressure It may further include a pressure sensor 363 to measure the temperature and a temperature sensor 364 to measure the temperature), and the control unit 360 is connected to the control valve 361 and the flow rate, pressure, and measurement sensors 362,363,364 and wired or wirelessly. It can be configured to be controllable.

The control unit 360 compares the physical properties transmitted from the measurement sensors 362, 363, and 364 with the physical properties of the liquefied gas to satisfy the effective suction head of the high-pressure pump 320, and the boil-off gas-recondenser supply line (L5a) on the pipe type ash The flow rate of the boil-off gas supplied to the condenser 310 may be controlled.

Specifically, when the flow rate received from the flow rate sensor 362 is less than or equal to a preset flow rate, the control unit 360 increases the opening rate of the control valve 361 to increase the BOG-recondenser supply line L5a in the pipe type Control to increase the flow rate of BOG supplied to the recondenser 310, and when the flow rate received from the flow rate sensor 362 exceeds a preset flow rate, the opening rate of the control valve 361 is reduced to increase BOG - It is possible to control to reduce the flow rate of boil-off gas supplied from the recondenser supply line (L5a) to the pipe type recondenser (310).

In addition, when the pressure received from the pressure sensor 363 is less than or equal to the preset pressure, the control unit 360 increases the opening rate of the control valve 361 to thereby increase the boil-off gas-recondenser supply line L5a. Control to increase the flow rate of boil-off gas supplied to the condenser 310, and when the pressure received from the pressure sensor 363 exceeds a preset pressure, the opening rate of the control valve 361 is reduced to reduce the boil-off gas- It can be controlled to reduce the flow rate of boil-off gas supplied to the pipe-type recondenser 310 from the recondenser supply line (L5a).

In addition, when the temperature received from the temperature sensor 364 is less than or equal to the preset temperature, the control unit 360 increases the opening rate of the control valve 361 to increase the boil-off gas-recondenser supply line L5a in the pipe type material. Control to increase the flow rate of boil-off gas supplied to the condenser 310, and when the temperature received from the temperature sensor 364 exceeds the preset temperature, the opening rate of the control valve 361 is reduced to reduce the boil-off gas- It can be controlled to reduce the flow rate of boil-off gas supplied to the pipe-type recondenser 310 from the recondenser supply line (L5a).

In addition, the control unit 360 may receive the physical property values from each of the measurement sensors 362 to 364 as described above, and may be controlled in combination with each other.

For this reason, in the embodiment of the present invention, by satisfying the effective suction head of the high-pressure pump 320 through the control unit 360, the high-pressure pump 32 and the pipe-type recondenser 310 on the liquefied gas supply line L4. A buffer tank may not be provided in between, thereby reducing the construction cost.

In addition, the gas treatment system 300 according to the present invention controls the flow rate of the boil-off gas flowing into the pipe-type recondenser 310 through the state of the liquefied gas flowing into the high-pressure pump 320 , and the high-pressure pump 320 . Even if a buffer tank is not provided upstream of the , a stable liquefied gas inflow pressure to the high-pressure pump 320 can be stably secured, and the construction space can be optimized.

In addition, the gas processing system 300 according to the present invention can reduce the hourly flow rate of the BOG supplied to the BOG compressors 341 and 342 (100 to 200 kg/h), so that the BOG compressors 341 and 342 can reduce the work being driven. There is an effect of reducing the power consumption of the boil-off gas compressors 341 and 342 accordingly.

Here, in the embodiment of the present invention, when the flow rate, temperature, and pressure received from the measurement sensors 362, 363, and 364 exceed the preset flow rate, temperature, and pressure, the opening rate of the control valve 361 is reduced, so that the boil-off gas-recondenser The opening rate of the first bypass line L6a and the control valve 361 for supplying boil-off gas that cannot be supplied from the supply line L5a to the pipe-type recondenser 310 to the liquefied gas storage tank 10 is reduced. The BOG-recondenser supply line (L5a) further includes a second bypass line (L6b) for supplying BOG which cannot be supplied to the pipe-type recondenser 310 to the upstream of the first BOG compressor 341 . can do.

In addition, in the embodiment of the present invention, the control unit 360 may control through the first BOG compressor 341 in addition to the control through the control valve 361 .

Specifically, when the physical properties (flow rate, temperature, pressure) received from the measurement sensors 362, 363, and 364 are less than or equal to the preset physical properties, the control unit 360 controls the driving performance of the first boil-off gas compressor 341 (for example, increase the RPM) control to increase the flow rate of boil-off gas supplied from the boil-off gas-recondenser supply line (L5a) to the pipe-type recondenser 310 by increasing In this case, by lowering the driving performance (eg, lowering the RPM) of the first BOG compressor 341, BOG-reducing the flow rate of BOG supplied from the recondenser supply line L5a to the pipe type recondenser 310 can be controlled to do so.

The boil-off gas compressors 341 and 342 are provided on the boil-off gas supply line L5 and compress the boil-off gas generated in the liquefied gas storage tank T and supply the first evaporation to the pipe-type recondenser 310 . It is provided downstream of the BOG-recondenser supply line L5a on the gas compressor 341 and the BOG supply line L5, and further compresses the BOG compressed in the first BOG compressor 341 to provide a propulsion engine ( It may be divided into a second boil-off gas compressor 342 supplied to E). At this time, the boil-off gas-recondenser supply line (L5a) may have a branched form downstream of the first boil-off gas compressor 341 on the boil-off gas supply line (L5), and the first boil-off gas compressor 341, All of the boil-off gas generated in the liquefied gas storage tank T is compressed, and the second boil-off gas compressor 342 may compress at least a portion of the boil-off gas compressed in the first boil-off gas compressor 341 .

In addition, the boil-off gas compressors 341 and 342, the first boil-off gas compressor 341 and evaporation for supplying at least a portion of the boil-off gas generated in the liquefied gas storage tank T to the pipe-type recondenser 310 by compression. It may be divided into a second BOG compressor 342 provided on the gas supply line L5, which compresses at least a portion of BOG generated in the liquefied gas storage tank T and supplies it to the propulsion engine E. . At this time, the BOG-recondenser supply line (L5a) may be formed separately from the BOG supply line (L5) in parallel, and the first and second BOG compressors (341 and 342) are in the liquefied gas storage tank (T). Each of the generated boil-off gases may be compressed at least in part.

6 is a conceptual diagram of a gas processing system according to a fourth embodiment of the present invention.

As shown in Figure 6, the gas treatment system 400 according to the embodiment of the present invention, a liquefied gas storage tank (T), a feeding pump (P), a propulsion engine (E), a pipe type recondenser (410) , including a high-pressure pump 420 , a vaporizer 430 , and an ejector 440 .

Hereinafter, a gas processing system 400 according to an embodiment of the present invention will be described with reference to FIG. 6 .

Before describing the individual components of the gas processing system 400 according to the embodiment of the present invention, basic flow paths that organically connect the individual components will be described. Here, the flow path is a passage through which the fluid flows and may be a line.

In the embodiment of the present invention, liquefied gas supply line (L4), liquefied gas return line (L4a), boil-off gas-ejector suction line (L4b), liquefied gas-recondenser supply line (L4c), boil-off gas consumer supply line ( L4d) may be further included. Valves (not shown) capable of adjusting the opening degree may be installed in each line, and the supply amount of boil-off gas or liquefied gas may be controlled according to the adjustment of the opening degree of each valve.

The liquefied gas supply line (L4) connects the liquefied gas storage tank (T) and the propulsion engine (E), and includes a feeding pump (P), a pipe type recondenser (410), a high pressure pump (420), and a carburetor (430). And an ejector 440 may be provided to supply the liquefied gas stored in the liquefied gas storage tank (T) to the propulsion engine (E).

The liquefied gas return line L4a is branched between the pipe type recondenser 410 and the high pressure pump 420 on the liquefied gas supply line L4 and is connected to the liquefied gas storage tank T, and the pipe type recondenser ( When the re-condensation gas discharged from 410 is not completely re-condensed, the re-condensation gas discharged from the pipe-type re-condenser 410 may be returned to the liquefied gas storage tank (T).

The BOG-ejector suction line L4b connects the ejector 440 and the liquefied gas storage tank T, and may supply BOG generated in the liquefied gas storage tank T to the ejector 440 .

The liquefied gas-recondenser supply line (L4c) is branched from the upstream of the ejector 440 on the liquefied gas supply line (L4) and connected to the pipe-type recondenser 410, and the liquefied gas supplied by the feeding pump (P) At least a portion of the gas may be supplied to the pipe-type recondenser 410 .

The boil-off gas consumer supply line (L4d) is branched between the carburetor 430 and the propulsion engine E on the liquefied gas supply line L4 and is connected to the power generation engine 451 and the gas combustion device 452, and the carburetor ( At least a portion of the vaporized gas supplied from the 430 may be supplied to the power generation engine 451 and the gas combustion device 452 .

Hereinafter, individual components that are organically formed by each of the above-described lines L4 to L4d to implement the gas processing system 400 will be described.

In an embodiment of the present invention, the configuration of the liquefied gas storage tank (T), the feeding pump (P), the propulsion engine (E), the high-pressure pump 420 and the carburetor 430 is a gas according to the first embodiment of the present invention The configuration of the liquefied gas storage tank 70 for shipping, the pump 21 for fuel supply, the propulsion engine 60 and the carburetor 30 in the processing system 100 and the gas processing system according to the second embodiment of the present invention Since it is the same as the configuration of the high-pressure pump 230 in 200, it should be replaced.

The pipe type recondenser 410 is provided between the ejector 440 and the high-pressure pump 420 on the liquefied gas supply line L4, and the ejector 440 through the liquefied gas supplied from the liquefied gas storage tank T. The mixed gas discharged from the is re-condensed.

At this time, the pipe-type recondenser 410 may receive liquefied gas from the liquefied gas-recondenser supply line L4c branched upstream of the ejector 440 on the liquefied gas supply line L4.

That is, the pipe-type recondenser 410 completely recondenses the mixed gas discharged from the ejector 440 through the liquefied gas supplied from the liquefied gas storage tank T, and supplies it to the high-pressure pump 420. Even without a buffer tank, the effective suction head (NPSH) of the high-pressure pump 420 can be satisfied.

As a result, system construction cost is reduced, system reliability is improved, and driving safety is maximized.

The ejector 440 is provided on the liquefied gas supply line L4, and sucks the boil-off gas generated from the liquefied gas storage tank T through the liquefied gas supplied from the liquefied gas storage tank T.

Specifically, the ejector 440 is provided between the feeding pump P on the liquefied gas supply line L4 and the pipe-type recondenser 410, and the boil-off gas - through the ejector suction line L4b, the liquefied gas storage tank ( T), the BOG generated in the liquefied gas storage tank (T) through the liquefied gas supplied through the liquefied gas supply line (L4) is sucked through the BOG-ejector suction line (L4b) and mixed. , can be supplied to the pipe type recondenser 410 .

Through this, the cavitation problem that may occur when the ejector 440 is used to supply the high-pressure pump 420 can be solved through the pipe-type recondenser 410, thereby improving system safety. In addition, since the ejector 440 has a simple structure due to the nature of the configuration, system reliability is improved, and space utilization is increased by reducing the construction space.

7 is a conceptual diagram of a gas processing system according to a fifth embodiment of the present invention.

7, the gas treatment system 500 according to the embodiment of the present invention is a liquefied gas storage tank (T), a feeding pump (P), a propulsion engine (E), a pipe type recondenser (511, 512 ), a high pressure pump 521 , a vaporizer 522 , a heater 523 , a reliquefaction device 530 , a high pressure BOG compressor 541 , a low pressure BOG compressor 542 , and a condensing tank 560 . .

Hereinafter, a gas processing system 500 according to an embodiment of the present invention will be described with reference to FIG. 7 .

Before describing the individual components of the gas processing system 500 according to the embodiment of the present invention, basic flow paths that organically connect the individual components will be described. Here, the flow path is a passage through which the fluid flows and may be a line.

In an embodiment of the present invention, a liquefied gas supply line (L4), a condensing tank supply line (L4e), a boil-off gas supply line (L5), a low pressure boil-off gas compressor supply line (L5c), a re-liquefaction device supply line (L5d), The recondenser first branch line (L5e) and the recondenser second branch line (L5f) may be further included. Valves (not shown) capable of adjusting the opening degree may be installed in each line, and the supply amount of boil-off gas or liquefied gas may be controlled according to the adjustment of the opening degree of each valve.

The liquefied gas supply line (L4) connects the liquefied gas storage tank (T) and the propulsion engine (E), and includes a feeding pump (P), a pipe type recondenser (511), a high pressure pump (521), and a carburetor (522). And a heater 523 can be provided to supply the liquefied gas stored in the liquefied gas storage tank (T) to the propulsion engine (E).

The condensing tank supply line L4e is branched between the pipe-type recondenser 511 and the high-pressure pump 521 on the liquefied gas supply line L4 and high-pressure or low-pressure boil-off gas compressors 541 and 542 on the boil-off gas supply line L5. ) is connected to the upstream, and may be provided with a condensing tank (560).

In this case, the condensing tank supply line L4e may supply the boil-off gas generated in the condensing tank 560 to the boil-off gas supply line L5.

The low-pressure BOG compressor supply line L5c is branched from the high-pressure BOG compressor 541 upstream on the BOG supply line L5 and may be connected to the pipe-type recondensers 511 and 512, respectively, and a liquefied gas storage tank (T) A low-pressure BOG compressor 542 may be provided to compress the BOG generated in the low pressure and supply it to the pipe-type recondenser (first recondenser; 512).

The reliquefaction device supply line L5d may branch from the downstream of the high pressure BOG compressor 541 and be connected to the liquefied gas storage tank T, and may include a reliquefaction device 530 .

The recondenser first branch line (L5e) is branched from the upstream of the reliquefaction apparatus 530 on the reliquefaction apparatus supply line L5d, and may be connected to the pipe type recondenser 512 downstream of the reliquefaction apparatus 530. have.

The recondenser second branch line L5f is branched from the downstream of the low pressure BOG compressor 542 on the low pressure BOG compressor supply line L5c and may be connected to the pipe type recondenser (second recondenser; 511).

Hereinafter, individual components that are organically formed by each of the above-described lines L4 to L5f to implement the gas processing system 500 will be described.

In an embodiment of the present invention, the configuration of the liquefied gas storage tank (T), the feeding pump (P), the propulsion engine (E), the high pressure pump 521 and the carburetor 522 is a gas according to the first embodiment of the present invention The configuration of the liquefied gas storage tank 70 for shipping, the pump 21 for fuel supply, the propulsion engine 60 and the carburetor 30 in the processing system 100 and the gas processing system according to the second embodiment of the present invention Since it is the same as the configuration of the high-pressure pump 230 in 200, it should be replaced.

The pipe type recondensers 511 and 512 may be divided into a pipe type recondenser 512 which may be referred to as a first recondenser and a pipe type recondenser 511 which may be referred to as a second recondenser. Hereinafter, please note that the pipe type recondenser 512 may be used as a first recondenser and the pipe type recondenser 511 may be used as a second recondenser.

The first recondenser 512 is formed between the reliquefaction device 530 and the liquefied gas storage tank (T) on the reliquefaction device supply line (L5d; the name may be used interchangeably with the reliquefaction line), and the recondenser first It is connected to the first branch line (L5e) and re-condensates the boil-off gas supplied from the recondenser first branch line (L5e) through the liquefied gas supplied from the re-liquefaction device 530 .

In the embodiment of the present invention, when the pressure upstream of the reliquefaction device 530 is greater than or equal to the preset pressure, at least a portion of the boil-off gas supplied to the reliquefaction device 530 is transferred to the first ash through the recondenser first branch line L5e. It may further include a first control unit (not shown) for controlling the supply to the condenser 512 .

Accordingly, in the embodiment of the present invention, the first control valve V1 provided on the recondenser first branch line L5e and controlling the BOG flow on the recondenser first branch line L5e and the reliquefaction device are supplied. It may further include a pressure sensor (not shown) provided upstream of the reliquefaction apparatus 530 on the line L5d to measure the pressure of the boil-off gas flowing into the reliquefaction apparatus 530, and the first control unit 1 may be configured to be controlled by being connected to the control valve (V1) and the pressure sensor by wire or wirelessly. In this case, the pressure sensor may measure the pressure of the boil-off gas flowing into the reliquefaction apparatus 530 and transmit the measured pressure value to the first control unit by wire or wirelessly.

When the pressure upstream of the reliquefaction device 530 becomes greater than or equal to a preset pressure, the first control unit opens the opening degree of the first control valve V1 to at least a portion of the boil-off gas supplied to the reliquefaction device 530 . is controlled to be supplied to the first recondenser 512 through the recondenser first branch line L5e, and when the upstream pressure of the reliquefaction device 530 becomes less than the preset pressure, the first control valve V1 ), it is possible to control so that all of the boil-off gas supplied to the reliquefaction apparatus 530 is supplied to the reliquefaction apparatus 530 by closing the opening.

As such, in the gas treatment system 500 according to the present invention, a pipe type recondenser 512 is installed downstream of the reliquefaction apparatus 530 , and the reliquefaction apparatus 530 is bypassed to the pipe type recondenser ( By installing the recondenser first branch line (L5e) connected to 512, there is an effect that can reduce the energy consumption of the reliquefaction device (530).

The second recondenser 511 is formed between the feeding pump P and the high pressure pump 521 on the liquefied gas supply line L4 and is connected to the recondenser second branch line L5f, from the feeding pump P The boil-off gas supplied from the second branch line L5f of the recondenser is recondensed through the supplied liquefied gas.

In the embodiment of the present invention, when the internal pressure of the liquefied gas storage tank (T) is greater than or equal to the preset internal pressure, at least a portion of the boil-off gas generated in the liquefied gas storage tank (T) through the low-pressure boil-off gas compressor (542) is first recycled Controlled to be supplied to the condenser 512, and if the load of the propulsion engine E is greater than or equal to the preset load, at least a portion of the boil-off gas compressed through the low-pressure boil-off gas compressor 542 is supplied to the second re-condenser 511. It may further include a second control unit (not shown) for controlling.

Accordingly, in the embodiment of the present invention, the second adjustment is provided upstream of the low pressure BOG compressor 542 on the low pressure BOG compressor supply line L5c and controls the flow rate of BOG supplied to the low pressure BOG compressor 542 . Valve (V2), provided on the recondenser second branch line (L5f), the third control valve (V3) for controlling the flow of boil-off gas on the recondenser second branch line (L5f), liquefied gas storage tank (T) It may further include a pressure sensor (not shown) for measuring the internal pressure of the load sensor (not shown) for measuring the load of the propulsion engine (E), the second control unit is the second and third control valve (V2) ,V3) and the pressure and load sensors can be connected and controlled by wire or wirelessly.

The second control unit, when the internal pressure of the liquefied gas storage tank (T) is greater than or equal to the preset internal pressure, by opening the second control valve (V2), through the low pressure boil-off gas compressor (542) in the liquefied gas storage tank (T) At least a portion of the generated boil-off gas is controlled to be supplied to the first recondenser 512, and when the internal pressure of the liquefied gas storage tank T is less than the preset internal pressure, the second control valve V2 is closed to liquefy All of the BOG generated in the gas storage tank T may be controlled to be supplied to the high-pressure BOG compressor 541 .

In addition, the second control unit, when the load of the propulsion engine (E) is greater than or equal to the preset load, by opening the third control valve (V3), at least a portion of the boil-off gas compressed through the low pressure boil-off gas compressor (542) 2 is controlled to be supplied to the recondenser 511, and when the load of the propulsion engine E is less than the preset load, the third control valve V3 is closed, and BOG compressed through the low pressure BOG compressor 542 All of it can be controlled to be supplied to the first recondenser (512).

As described above, the gas treatment system 500 according to the present invention is a re-liquefaction device 530 for re-liquefying BOG, in addition to the high-pressure BOG compressor 541 that compresses and supplies BOG, as well as pipe-type recondensers 511 and 512. By additionally providing a low-pressure boil-off gas compressor 542 that compresses and supplies boil-off gas, the energy of the reliquefaction apparatus 530 can be reduced and the net energy consumption of the boil-off gas compressors 541 and 542 can be reduced.

The heater 523 is provided on the downstream side of the vaporizer 522 on the liquefied gas supply line L4, and the vaporized liquefied gas supplied from the vaporizer 522 is heated to match the temperature required by the propulsion engine E. can

The heater 523 may use various heating mediums such as seawater, fresh water, glycol water, etc. as a heat source, and the type is not particularly limited in the present invention.

The reliquefaction device 530 may reliquefy at least a portion of the BOG compressed in the high-pressure BOG compressor 541 through a separate refrigerant by providing a separate refrigerant device.

The high-pressure BOG compressor 541 is provided on the BOG supply line L5, and may compress BOG generated in the liquefied gas storage tank T at a high pressure and supply it to the propulsion engine E.

The low-pressure BOG compressor 542 is provided on the low-pressure BOG compressor supply line L5c, and compresses BOG generated in the liquefied gas storage tank T to a low pressure to a first re-condenser 511 and a second It can be supplied to the recondenser (512).

The condensing tank 560 is provided on the condensing tank supply line L4e, and stores at least a portion of the liquefied gas supplied from the second recondenser 511 .

In an embodiment of the present invention, the second recondenser 511 may be controlled as follows through structural coupling with the condensing tank 560 while being controlled by the first and second controllers.

The second recondenser 511, when the internal pressure of the liquefied gas storage tank (T) is equal to or greater than the preset pressure, at least a portion of the boil-off gas generated in the liquefied gas storage tank (T) through the low pressure boil-off gas compressor (542) Received and re-condensed through the liquefied gas supplied through the liquefied gas supply line (L4), and at the same time, when the load of the propulsion engine (E) is less than the preset load, at least a portion of the re-condensed liquefied gas is condensed in the condensing tank 560 ) can be supplied.

In an embodiment of the present invention, the fourth control valve (condensing tank control valve; V4) is provided upstream of the condensing tank 560 on the condensing tank supply line L4e, and controls the flow of liquefied gas supplied to the condensing tank 560. ) and a third control unit (not shown) for adjusting the opening degree of the second control valve (V2) and the fourth control valve (V4) according to the internal pressure of the liquefied gas storage tank (T) and the load of the propulsion engine (E) may include more.

Accordingly, in the embodiment of the present invention, the third control unit measures the load of the pressure sensor and the propulsion engine (E) for measuring the internal pressure of the second and fourth control valves (V2, V4) and the liquefied gas storage tank (T) It may be configured to be controlled by being connected to the load sensor by wire or wirelessly.

The third control unit, when the internal pressure of the liquefied gas storage tank (T) is equal to or greater than the preset pressure, by opening the opening degree of the second control valve (V2), at least a portion of the boil-off gas compressed in the low-pressure boil-off gas compressor (542) Control to be supplied to the second recondenser 511, but at the same time when the load of the propulsion engine (E) is less than the preset load, by opening the opening degree of the fourth control valve (V4) by the second recondenser (511) At least a portion of the recondensed liquefied gas is supplied to the condensing tank 560 through the condensing tank supply line L4e and controlled to be stored, and when the internal pressure of the liquefied gas storage tank T is less than the preset pressure, the second adjustment By closing the opening of the valve V2, the BOG is prevented from flowing into the low pressure BOG compressor 542 so that all BOG generated in the liquefied gas storage tank T is accumulated in the liquefied gas storage tank T. Alternatively, it can be supplied to the high-pressure BOG compressor 541 to return to the liquefied gas storage tank T after re-liquefaction through the re-liquefaction device 530, and at the same time, the load of the propulsion engine E is set to a preset load. When the above occurs, it is possible to control so that all of the liquefied gas recondensed by the second recondenser 511 can be supplied to the propulsion engine E by closing the opening of the fourth control valve V4.

Through this, the gas treatment system 500 according to the present invention further includes a condensing tank 560 for storing excess liquefied gas downstream of the pipe-type recondenser 511, so that the energy of the ship 3 can be efficiently used. There is an effect that can reduce the thermal load of the liquefied gas storage tank (T).

Although the present invention has been described in detail through specific examples, this is for the purpose of describing the present invention in detail, and the present invention is not limited thereto, and by those of ordinary skill in the art within the technical spirit of the present invention. It will be clear that the transformation or improvement is possible.

All simple modifications and variations of the present invention fall within the scope of the present invention, and the specific scope of protection of the present invention will be made clear by the appended claims.

1: Bunkering vessel 2,3: LNG-powered vessel
10: liquefied gas storage tank for unloading 20: pump for unloading
21: fuel supply pump 30: carburetor
40: pipe type recondenser 50: boil-off gas compressor
60: propulsion engine 61: boil-off gas consumer
70: liquefied gas storage tank for shipping 80: liquefied gas storage tank for propulsion
81: fuel supply pump 82: fuel processing system
83: propulsion engine 100: gas treatment system
B1, B2: Buffer tank T: Liquefied gas storage tank
P: Feeding pump E: Propulsion engine
S: Shaft P: Propeller
V: control valves V1 to V4: first to fourth control valves
200: gas treatment system 210: pipe type recondenser
220: buffer tank 230: high pressure pump
240: carburetor 250: boil-off gas compressor
300: gas treatment system 310: pipe type recondenser
320: high pressure pump 330: carburetor
341: first boil-off gas compressor 342: second boil-off gas compressor
351: power generation engine 352: gas combustion device
360: control unit 361: control valve
362: flow sensor 363: pressure sensor
364: temperature sensor 400: gas treatment system
410: pipe type recondenser 420: high pressure pump
430: carburetor 440: ejector
451: power generation engine 452: gas combustion device
500: gas treatment system 511: pipe type recondenser
512: pipe type recondenser 521: high pressure pump
522: carburetor 523: heater
530: reliquefaction unit 541: high-pressure boil-off gas compressor
542: low pressure boil-off gas compressor 551: power generation engine
552: gas combustion device 560: condensing tank
L1: Bunkering line L2: BOG return line
L2a: BOG liquefaction line L2b: BOG branch line
L2c: BOG consumer supply line L3: Liquefied gas supply line
L4: Liquefied gas supply line L4a: Liquefied gas return line
L4b: BOG-Ejector Suction Line L4c: Liquefied Gas-Recondenser Supply Line
L4d: BOG consumer supply line L4e: Condensing tank supply line
L5: BOG supply line L5a: BOG-recondenser supply line
L5b: BOG consumer supply line L5c: Low pressure BOG compressor supply line
L5d: reliquefaction unit supply line L5e: recondenser first branch line
L5f: recondenser second branch line L6a: first bypass line
L6b: second bypass line

Claims (9)

a liquefied gas supply line connecting the liquefied gas storage tank and the customer;
a suction device provided on the liquefied gas supply line and sucking boil-off gas generated from the liquefied gas storage tank through the liquefied gas supplied from the liquefied gas storage tank;
a recondenser provided on the liquefied gas supply line and recondensing the mixed gas discharged from the suction device through the liquefied gas supplied from the liquefied gas storage tank;
a pump provided downstream of the recondenser on the liquefied gas supply line and pressurizing the liquefied gas supplied from the recondenser;
Further comprising a liquefied gas return line branched between the recondenser and the pump on the liquefied gas supply line and connected to the liquefied gas storage tank,
The liquefied gas return line,
When the recondensing gas discharged from the recondenser is not completely recondensed, the recondensing gas discharged from the recondenser is returned to the liquefied gas storage tank. The method of claim 1, wherein the recondenser,
By completely recondensing the mixed gas discharged from the suction device through the liquefied gas supplied from the liquefied gas storage tank and supplying it to the pump, the effective suction head of the pump is satisfied without a separate buffer tank. processing system. delete 3. The method of claim 2,
The pump is a high pressure pump,
a feeding pump provided upstream of the suction device on the liquefied gas supply line and supplying the liquefied gas stored in the liquefied gas storage tank to the suction device; and
and a vaporizer provided downstream of the high-pressure pump on the liquefied gas supply line to vaporize the liquefied gas supplied from the high-pressure pump. According to claim 1, wherein the suction device,
Gas processing system, characterized in that the ejector (Ejector). The method of claim 1, wherein the recondenser,
A gas treatment system, characterized in that it is a pipe type recondenser (Inline type recondenser). The method of claim 1,
and a BOG-ejector suction line connecting the suction device and the liquefied gas storage tank and supplying BOG generated from the liquefied gas storage tank to the suction device. 8. A vessel comprising the gas treatment system of any one of claims 1, 2, 4-7. A Floating Offshore Structure (FSRU) comprising the gas processing system of any one of claims 1, 2, 4-7.

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