WO2016200170A1

WO2016200170A1 - Vessel comprising gas treatment system

Info

Publication number: WO2016200170A1
Application number: PCT/KR2016/006118
Authority: WO
Inventors: 임원섭; 이동진
Original assignee: 현대중공업 주식회사
Priority date: 2015-06-09
Filing date: 2016-06-09
Publication date: 2016-12-15

Abstract

The vessel comprising a gas treatment system according to the present invention is characterized by effectively reliquefying boil-off gas by means of a reliquefaction apparatus for reliquefying the boil-off gas, which is not supplied to a high-pressure gas injection engine, and an expansion valve provided downstream of the reliquefaction apparatus. Further, the present invention is capable of increasing the stability and reliability of the system by effectively supplying liquefied gas and boil-off gas from a liquefied gas storage tank to a consumer.

Description

Vessels Including Gas Treatment Systems

The present invention relates to a vessel comprising a gas treatment system.

A ship is a means of transporting the ocean carrying large quantities of minerals, crude oil, natural gas, or thousands of containers. It is made of steel and is buoyant and floats on the water surface by buoyancy. Go through.

These vessels generate thrust by driving the engine, where the engine uses gasoline or diesel to move the piston so that the crankshaft is rotated by the reciprocating movement of the piston, whereby the shaft connected to the crankshaft rotates to drive the propeller. It was common to make it possible.

Recently, however, an LNG fuel supply method for driving an engine using LNG as a fuel has been used in an LNG carrier carrying Liquefied Natural Gas. It is also applied to other ships.

In general, LNG is known to be a clean fuel and abundant reserves than petroleum, and its use is rapidly increasing with the development of mining and transportation technology. It is common to store LNG in liquid state by reducing the temperature of methane, the main component, below -162 degrees under 1 atm, and the volume of liquefied methane is about 600% of the volume of gaseous methane in the standard state. Is 0.42, which is about one half of the share of crude oil.

However, the temperature and pressure required for the customer to operate may be different from the state of LNG stored in the tank. Therefore, in recent years, continuous research and development has been made regarding a technology for controlling the temperature and pressure of LNG stored in a liquid state and supplying it to a demand destination.

In addition, when LNG is stored in the liquid phase, as the heat penetrates into the tank, some LNG is vaporized to generate boil off gas (BOG). In the past, the boil off gas (BOG) was lowered to remove the risk of damage to the tank. It was simply discharged to the outside. However, in recent years, the necessity of development is gradually increasing for the utilization method such as reliquefaction of the boil-off gas generated in the tank and supplying it to the customer.

The present invention was created to solve the problems of the prior art as described above, an object of the present invention is to provide a vessel including a gas treatment system for effectively supplying liquefied gas and / or boil off gas from the liquefied gas storage tank to the demand. It is to.

The ship including the gas treatment system according to an embodiment of the present invention, the first line for connecting the liquefied gas storage tank and the high-pressure gas injection engine; A second line branching from the first line; A reliquefaction apparatus provided on the second line and configured to heat-exchange the remaining evaporated gas not supplied to the high-pressure gas injection engine with a refrigerant; And an expansion valve provided downstream of the reliquefaction apparatus and expanding the boil-off gas.

Specifically, the boil-off gas compressor provided on the first line; And a pressure reducing valve provided upstream of the reliquefaction apparatus on the second line and configured to reduce the boil-off gas compressed by the boil-off gas compressor and branched.

Specifically, the second line may be branched at an intermediate stage of the boil-off compressor.

Specifically, the boil-off gas branched at the intermediate stage of the boil-off gas compressor and compressed at low pressure is primarily depressurized to 7 bar to 8 bar through the pressure reducing valve, cooled through the reliquefaction device, and 5 bar through the expansion valve. Can be reduced to secondary pressure to 6 bar.

Specifically, the apparatus further includes a third line branched between the pressure reducing valve and the reliquefaction device to be connected to a gas combustion device (GCU), wherein the third line is a normal pressure at which the liquefied gas storage tank is internally safe. In the pressure range, when the internal pressure of the liquefied gas storage tank is higher than the normal pressure range, at least a portion of the boil-off gas branched from the intermediate stage of the boil-off gas compressor and compressed to low pressure may be supplied to the gas combustion device. .

In detail, the gas-liquid separator may further include a gas-liquid separator for separating the re-liquefied boil-off gas through the expansion valve into a gas phase and a liquid phase.

Specifically, the gas-liquid separator, the separated gas phase is supplied to a gas combustion device (GCU) consuming a flash gas, the separated liquid phase may be returned to the liquefied gas storage tank.

Specifically, the fourth line connecting the gas-liquid separator and the liquefied gas storage tank; A pump provided on the fourth line to return the liquid liquefied gas stored in the gas-liquid separator to the liquefied gas storage tank; And a fifth line bypassing the pump.

Specifically, the liquid liquefied gas stored in the gas-liquid separator is supplied to the liquefied gas storage tank by bypassing the pump through the fifth line when the internal pressure of the gas-liquid separator is greater than or equal to a predetermined pressure value, and the gas-liquid separator When the internal pressure of less than a predetermined pressure value, it can be supplied to the liquefied gas storage tank through the pump.

Specifically, the preset pressure value may be 5bar to 6bar.

Specifically, the reliquefaction apparatus, using a nitrogen refrigerant or a mixed refrigerant as a refrigerant, the first liquefier of the boil-off gas, may be a Joule-Thomson valve.

Specifically, the method may further include a sixth line branched from the first line and connected to the heterogeneous fuel power generation engine, and the second line may branch on the sixth line.

The vessel including the gas treatment system according to the present invention can effectively supply liquefied gas and / or boil-off gas to a demand destination in a liquefied gas storage tank to increase system stability and reliability.

1 is a conceptual diagram of a gas treatment system according to an embodiment of the present invention.

2A is a conceptual diagram of a vaporization system in the gas treatment system of the present invention.

2B is a conceptual diagram of a vaporization system in the gas treatment system of the present invention.

2C is a conceptual diagram of a vaporization system in the gas treatment system 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 the preferred embodiments associated with the accompanying drawings. In the present specification, in adding reference numerals to the components of each drawing, it should be noted that the same components as possible, even if displayed on different drawings have the same number as possible. In addition, in describing the present invention, if it is determined that the detailed description of the related known technology may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

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

Hereinafter, the liquefied gas may be LPG, LNG, ethane, etc. For example, it may mean LNG (Liquefied Natural Gas), and the evaporated gas may mean BOG (Boil Off Gas), which is natural vaporized LNG.

Liquefied gas may be referred to regardless of the change of state, such as liquid state, gas state, liquid and gas mixed state, subcooled state, supercritical state, etc., it is also known that evaporated gas is the same. In addition, the present invention is not limited to the liquefied gas to be treated, it may be a liquefied gas treatment system and / or boil-off gas treatment system.

Referring to FIG. 1, a gas treatment system according to an embodiment of the present invention may be mounted on a vessel such as an LNG carrier, a liquefied gas storage tank 10, a demand destination 20, an evaporative gas compressor 30, A boosting pump 40, a high pressure pump 41, a vaporizer 42, and a forced vaporizer 50.

Hereinafter, each configuration of the gas treatment system 1 according to the embodiment of the present invention will be described, and after the description of the configuration is completed, each embodiment through the relationship between the configurations of the system will be described.

In an embodiment of the present invention, the first to thirteenth lines L1 to L13 may be further included. Each line may be provided with valves (not shown) that can adjust the opening degree, and the supply amount of the boil-off gas and / or the liquefied gas and / or various refrigerants may be controlled according to the opening degree of each valve.

The liquefied gas storage tank 10 can store liquefied gas of -163 degrees. The liquefied gas storage tank 10 may be a tank such as a standalone type, a membrane type, a pressurized type, or the like, and the size, shape, structure, and the like are not particularly limited as long as the liquefied gas can be stored.

The liquefied gas storage tank 10 may have a mixture of a liquefied gas in a liquid state and a vaporized gas in a gaseous state. This is because an external heat penetrates into the liquefied gas storage tank 10 so that the liquefied gas is heated so that the boil-off gas may be generated.

At this time, since the boil-off gas causes an increase in the internal pressure of the liquefied gas storage tank 10 as the flow rate increases, it is preferable to discharge the gas for the protection of the liquefied gas storage tank 10. Therefore, the present invention can properly discharge the boil-off gas in accordance with the pressure of the liquefied gas storage tank (10).

The discharged boil-off gas may be burned away by a gas combustion unit 23 to be described later, or may be supplied to and consumed by a demand destination 20 (engine, turbine, boiler, etc.).

Alternatively, the boil-off gas discharged from the liquefied gas storage tank 10 is cooled below the boiling point by a reliquefaction apparatus 37 or the like to be liquefied into a liquid state in a gas state (the same as liquefied gas with liquefied boil-off gas / Similar) to the liquefied gas storage tank 10, and the like.

The liquefied gas storage tank 10 may include a heat insulating part and a barrier part to prevent penetration of external heat.

The barrier portion may be provided on the inner side (side adjacent to the liquefied gas) relative to the heat insulation portion, and the insulation portion may be provided on the outer side (side adjacent to the hull) relative to the barrier portion. However, this may vary depending on the structure of the liquefied gas storage tank 10, and may be variously determined depending on whether the liquefied gas storage tank 10 is a membrane type, a standalone type, a pressurized type, or the like.

The heat insulation part insulates the inside and outside of the liquefied gas storage tank 10 using a heat insulating material. The heat insulating part forms a heat insulating structure by using various heat insulating materials such as polyurethane foam (PUF), perlite, and wood, and may include metal such as stainless steel (SUS) and invar (INVAR).

When the liquefied gas storage tank 10 is a membrane type, the insulation may be determined according to a conventionally well-known type such as Mark III, No. 96, and when the liquefied gas storage tank 10 is a stand-alone type, MOSS, SPB, etc. The structure can be determined according to the type well known in the art. Of course, the heat insulation part is not limited to the structure by said illustration.

The barrier part can insulate the inside and the outside of the liquefied gas storage tank 10 using an inert gas. The barrier part may form an empty space, and the empty part of the barrier part may be formed between the inner wall and the heat insulating part of the liquefied gas storage tank 10, and / or between the outer wall and the heat insulating part of the liquefied gas storage tank 10. .

The barrier part may be filled with an inert gas such as nitrogen, and the inert gas may be supplied by an inert gas supplier provided outside. In this case, the inert gas supply may use a nitrogen generator (N2 generator).

The demand destination 20 may be a configuration that consumes liquefied gas or the like (liquefied gas, evaporated gas or flash gas) and generates or burns energy while consuming liquefied gas or the like.

For example, the demand destination 20 may include a low pressure demand destination using liquefied gas having a pressure of about 1 bar to 10 bar (absolute pressure) such as a turbine low pressure engine (DFDE, DFDG, XDF, etc.), a reliquefaction device, a boiler, a gas combustion device, and the like. It may be a high pressure demand destination using a liquefied gas having a pressure of about 200 bar to 400 bar (absolute pressure), such as a high pressure engine (ME-GI engine, etc.), and the pressure of the liquefied gas required for each demand destination 20 may be different.

That is, in the present invention, the demand source 20 broadly means all the components consuming liquefied gas and the like, and the present invention does not limit the demand source 20 to the specific configuration.

In the embodiment of the present invention has a configuration of a gas supply unit for processing the liquefied gas or boil-off gas stored in the liquefied gas storage tank (10). Here, the gas supply unit is configured to deliver the liquefied gas and / or the evaporated gas to the demand destination 20 such as an engine, and the evaporated gas compressor 30, the boosting pump 40, the high pressure pump 41, the vaporizer 42, and the like. It may include.

The boil-off gas compressor 30 compresses the boil-off gas discharged from the liquefied gas storage tank 10. The boil-off gas compressor 30 may be formed of a centrifugal type, a reciprocating type, or the like, and the plurality of boil-off gas compressors 30 may constitute a boil-off gas compressor (not shown).

In this case, the plurality of boil-off gas compressors constituting the boil-off gas compression unit 30 may be provided such that all of them are centrifugal, all of reciprocating, or both of them.

In one example, the boil-off gas compressor 30 may include a reciprocating compressor and / or a centrifugal compressor, and the reciprocating compressor and the centrifugal compressor may be provided in parallel, wherein the discharge pressure of the reciprocating compressor and the centrifugal compressor is It can be the same or different.

For example, in the present invention, the boil-off gas compressor 30 may be composed of two stages, three stages, five stages, six stages, etc. in a centrifugal type. Each stage is merely compressed according to the requirements of the boil-off gas to be supplied according to the type of the customer 20, and the larger the stage, the larger the discharge pressure.

In addition, the boil-off gas compressor 30 may be configured as a cryogenic compressor to process boil-off gas in a low temperature state of about -100 degrees discharged from the liquefied gas storage tank 10. However, when the boil-off gas is compressed by the boil-off gas compressor 30, the temperature of the boil-off gas may rise, and thus, some of the upstream boil-off gas compressors of the multi-stage boil-off compressor included in the boil-off gas compression unit are cryogenic compressors. The remaining boil-off gas compressor may be a compressor for room temperature.

When the temperature of the boil-off gas is increased while the boil-off gas is compressed by the boil-off gas compressor 30, the volume of the boil-off gas may increase as the volume of the boil-off gas increases. This can lead to an unnecessary load increase of the boil-off gas compressor 30, upstream of at least one boil-off gas compressor 30 and / or downstream of at least one boil-off gas compressor 30, compressed evaporation. An evaporative gas cooler (not shown) may be provided to cool the gas.

The boil-off gas cooler may cool the boil-off gas by using various cooling heat sources. For example, the boil-off gas cooler may include seawater, re-liquefied refrigerant, liquefied gas, boil-off gas, flash gas, etc. of the reliquefaction apparatus 37. Can be used.

In addition to the boil-off gas cooler, a buffer tank (not shown) may be provided between each stage of the boil-off gas compressor 30. The buffer tank may be provided for the continuous supply of the boil-off gas flowing into each stage of the boil-off gas compressor 30 and the constant maintenance of the supply pressure.

The boil-off gas flowing into the boil-off gas compressor 30 may be heat-exchanged with the compressed boil-off gas. However, the boil-off gas introduced into the boil-off gas compressor 30 due to heat exchange may be preheated, and thus the boil-off gas compressor 30 may be configured as a compressor for room temperature.

The boil-off gas compressor 30 may compress the boil-off gas to about 10 bar (absolute pressure) to 400 bar (absolute pressure). This may vary depending on where the boil-off gas discharged from the boil-off gas compressor 30 is used.

For example, when the boil-off gas compressed by the boil-off gas compressor 30 is used in a low pressure demand source 22 such as a turbine, a low-pressure engine (DFDE, DFDG, XDF, etc.), a reliquefaction unit, a boiler, a gas combustion device, The pressure may be about 1 bar to 10 bar (absolute pressure), and when the compressed boil-off gas is used for high pressure demand 21 such as a high-pressure engine (ME-GI, etc.), the pressure of the compressed boil-off gas is about 200 bar to 400 bar (absolute pressure). May be).

Of course, the boil-off gas compressor 30 may be provided in multiple stages, and the boil-off gas compressed at a low pressure by some boil-off gas compressors 30 may be discharged to the outside of the boil-off gas compressor 30 to be used for the low-pressure demand destination 22. In addition, the boil-off gas further compressed to high pressure by the remaining boil-off gas compressor 30 may be discharged to the outside of the boil-off gas compressor 30 and used at the high-pressure demand destination 21.

That is, in the boil-off gas compressor having the boil-off gas compressor 30 provided in multiple stages, the pressure of the boil-off gas supplied to each demand destination 20, the number of boil-off gas compressors 30, the degree of multi-stage compression of the boil-off gas, etc. It can be variously determined without being limited.

In order to deliver the boil-off gas from the liquefied gas storage tank 10 to the low pressure demand 22 or the high pressure demand 21 via the evaporative gas compressor 30, the liquefied gas storage tank 10 is supplied to each demand destination 20. Lines (second, third, five, seven, eight lines L2, L3, L5, L7, L8, etc.) may be provided.

At this time, the supply line connected to the low pressure demand destination 22 from the boil-off gas compressor (end or middle end) may be a low-pressure supply line (third line L3), and the boil-off gas compressor 30 (end or middle end). In the supply line connected to the high pressure demand 21 may be a high pressure supply line (second line (L2)). Therefore, the supply line may be branched into a low pressure supply line (third line L3) and a high pressure supply line (second line L2) based on the boil-off gas compressor 30.

The boil-off gas compressor 30 passes through a portion of the boil-off gas compressor 30 provided in multiple stages, and the boil-off gas is compressed to low pressure and supplied to the low-pressure demand destination 22 along the low-pressure supply line L3. After passing through all of the boil-off gas compressors 30, the boil-off gas may be compressed to high pressure and supplied to the high pressure demand 21 along the high pressure supply line L2.

In the boil-off gas compressor 30, some may not use lubricating oil, and others may use lubricating oil. For example, when the boil-off gas compressor 30 is provided in five stages, the boil-off gas compressors of the first to third stages do not use lubricating oil (lubricating oil is not mixed with the boil-off gas), and the fourth to fifth stages use lubricating oil. May be incorporated into the boil-off gas. This is because, in the high pressure stage, as the pressure of the boil-off gas is changed to a high pressure, lubricating oil is required to smoothly drive the piston of the boil-off gas compressor 30.

Of course, the number of the boil-off gas compressor 30 is not limited to the above, and a part of the front end (low pressure stage) of the plurality of boil-off gas compressors 30 does not use lubricating oil, and the remainder of the rear end (high pressure stage) may use lubricating oil. .

The first pressure reducing valve 341 may depressurize or expand the boil-off gas pressurized by the boil-off gas compressor 30 and supplied to the reliquefaction apparatus 37. Although not shown here, the first pressure reducing valve 341 may reduce or expand the boil-off gas pressurized by the boil-off gas compressor 30 to supply not only the re-liquefaction device 37 but also the gas combustion device 23 and the like. .

The first pressure reducing valve 341 may be provided together with the second pressure reducing valve 342 to multi-stage reduce or expand the boil-off gas pressurized by the boil-off gas compressor 30. For example, the first pressure reducing valve 341 may be configured by first reducing the pressure or primary expansion of the boil-off gas pressurized by the boil-off gas compressor 30 or the boil-off gas branched at the intermediate end of the boil-off gas compressor 30. The boil-off gas, which is supplied to the liquefaction apparatus 37 and heat-exchanged in the reliquefaction apparatus 37, may be re-liquefied by secondary pressure reduction or secondary expansion through the second pressure reducing valve 342.

Techniques of the first pressure reducing valve 341 described above may be implemented by changing the configuration for each embodiment.

The gas-liquid separator 35 separates gas from the boil-off gas expanded or reduced at the first pressure reducing valve 341 or the second pressure reducing valve 342. In the gas-liquid separator 35, the boil-off gas is separated into a liquid and a gas so that the liquid is supplied to the liquefied gas storage tank 10, and the gas may be supplied to the gas combustion device 23 as a flash gas.

Here, the boil-off gas supplied to the gas-liquid separator 35 may be in a state of being cooled by being decompressed by the first pressure reducing valve 341 or the second pressure reducing valve 342. For example, the boil-off gas in the boil-off gas compressor 30 may be pressurized in multiple stages to have a pressure of 200 bar to 400 bar, and the temperature may be about 45 degrees. The boil-off gas raised to a temperature of about 45 degrees is recovered to the reliquefaction apparatus 37 through the first pressure reducing valve 341, and the boil-off gas heat-exchanged in the reliquefaction apparatus 37 is again the second pressure reducing valve 342. Is supplied. In this case, the boil-off gas in the first pressure reducing valve 341 or the second pressure reducing valve 342 may be cooled by a reduced pressure to have a pressure of about 1 bar and a temperature of about −162.3 degrees.

As such, in the present embodiment, the boil-off gas supplied to the gas-liquid separator 35 is decompressed (or multi-stage decompressed) in the first pressure reducing valve 341 or the second pressure reducing valve 342 to have a temperature lower than -162 degrees. For example, about 30 to 40% of the evaporated gas can be liquefied. Thereafter, the gas-liquid separator 35 recovers the liquefied gas to the liquefied gas storage tank 10 and the gas combustion device 232 through the ninth line L9 without discarding the flash gas generated in the gas-liquid separator 35. It can be supplied and burned.

The second pressure reducing valve 342 depressurizes or expands the boil-off gas pressurized by the boil-off gas compressor 30 and heat-exchanged in the reliquefaction apparatus 37 to liquefy at least a portion. For example, the second pressure reducing valve 342 may reduce the evaporated gas to 1 bar to 10 bar, and the evaporated gas may be liquefied to reduce the pressure to 1 bar when the liquefied gas is transferred to the liquefied gas storage tank 10. Cooling effect can be achieved.

Here, the boil-off gas pressurized by the boil-off gas compressor 30 is cooled by heat exchange with the boil-off gas supplied from the liquefied gas storage tank 10 in the reliquefaction apparatus 37, but the pressure is discharged from the boil-off gas compressor 30. The discharge pressure can be maintained. In this embodiment, the boil-off gas is reduced by using the second pressure reducing valve 342 to cool the boil-off gas, thereby liquefying the boil-off gas. At this time, the larger the pressure range to be reduced in pressure may increase the cooling effect of the boil-off gas, for example, the second pressure reducing valve 342 may reduce the boil-off gas pressurized to 300bar by the boil-off compressor 30 to 1bar.

The second pressure reducing valve 342 may be a Joule Thompson valve. Alternatively, the second pressure reducing valve 342 may be formed of an expander (not shown). In the case of the Joule Thomson valve, the reduced pressure can effectively cool the boil-off gas so that at least a portion of the boil-off gas is liquefied. In this case, the expander may also be made of an expander (not shown).

On the other hand, the expander can be driven without using a separate power, in particular, by utilizing the generated power as the power for driving the boil-off gas compressor 30, it is possible to improve the efficiency of the gas treatment system (1). Power transmission may be achieved, for example, by gear connection or after electric conversion.

The second pressure reducing valve 342 is pressure-reduced by the boil-off gas compressor 30 together with the above-described first pressure-reducing valve 341 to multi-stage pressure-reduced boil-off gas exchanged by the reliquefaction apparatus 37, or the boil-off gas compressor. (30) It is possible to reduce the pressure of the boil-off gas branched to the multi-stage supply, which can be flexibly applied by changing the configuration according to each embodiment.

The boosting pump 40 and the high pressure pump 41 may pressurize the liquefied gas such that the liquefied gas is at or close to the pressure required by the customer 20. In the present invention, the demand source 20 may be the high pressure demand destination 21 and the low pressure demand destination 22, and the pressure of the liquefied gas required for each demand destination 20 may be different. ) And the high pressure pump 41, or may be composed only of the boosting pump 40 or only the high pressure pump 41, and may be provided in various ways. That is, the pressure of the liquefied gas pressurized by the

pumps

40 and 41 may be variously determined from 10 bar to 400 bar (absolute pressure) according to the required pressure of the customer 20, and the present invention is not particularly limited thereto.

In this case, each of the boosting pump 40 and the high pressure pump 41 may be provided in plural, and one pump may be used as a main and the other pump may be used as a backup. Of course, two or more pumps can be driven simultaneously to lower the load.

Lines for supplying liquefied gas from the liquefied gas storage tank 10 to the pumps 40 and 41 (first and sixth lines; L1 and L6, etc.) may be connected and flow along the lines L1 and L6. Can be. At this time, the lines (L1, L6) for supplying the liquefied gas may be connected to the vaporizer 42 and / or the demand destination 20 to be described later so that the liquefied gas is delivered from the liquefied gas storage tank 10 to the demand destination 20. have.

Lines L1 and L6 for supplying liquefied gas are high pressure liquefied gas supply lines (first line; L1) connected from the liquefied gas storage tank 10 to the high pressure demand destination 21 via

pumps

40 and 41. And / or a low pressure liquefied gas supply line (sixth line; L6) connected from the liquefied gas storage tank 10 to the low pressure demand destination 22 via the pump 40. When the high pressure liquefied gas supply line L1 and the low pressure liquefied gas supply line L6 are simultaneously provided, the high pressure liquefied gas supply line L1 and the low pressure liquefied gas supply line L6 may be branched from one liquefied gas supply line. The branch point may be variously determined according to the required pressure of the customer 20 (for example, between the boosting pump 40 and the high pressure pump 41).

The vaporizer 42 heats the liquefied gas. The liquefied gas stored in the liquefied gas storage tank 10 is a cryogenic temperature of about -160 degrees, the required temperature of the liquefied gas required by the customer 20 may be 10 to 50 degrees (preferably about 45 degrees). Therefore, when the liquefied gas is to be delivered to the demand destination 20, a temperature rise of the liquefied gas is required.

Of course, when pressurizing the liquefied gas with the

pump

40, 41 may increase the temperature of the liquefied gas, but this is not enough, the vaporizer 42, the liquefied gas to separate the heat source (steam, glycol water, sea water, engine Exhaust gas, engine coolant, electricity, etc.).

In order to supply a heat source to the vaporizer 42, the present invention may include a vaporization fruit storage tank 421, a vaporization fruit circulation pump 422, a vaporization fruit supply device 423, and a vaporization heat exchanger 424.

The vaporization fruit storage tank 421 is a tank for temporarily storing the vaporization fruit as a heat source, and can stably maintain the supply amount of the vaporization fruit.

The vaporization fruit circulation pump 422 is a configuration for supplying the vaporization fruit from the vaporization fruit storage tank 421 to the vaporization heat exchanger 424, provided with a plurality may be connected in parallel or in series, when the vaporization fruit is a gas, A heat source compressor (not shown) may be provided in place of the vaporized fruit circulation pump 422.

The vaporization fruit supply device 423 heats the vaporization fruit. Since the vaporized fruit may be cooled while heating the liquefied gas in the vaporized heat exchanger 424, it is necessary to supplement heat with the cooled vaporized fruit. Therefore, the vaporized fruit may be heated by steam or the like and then heat the liquefied gas in the vaporized heat exchanger 424.

The vaporization fruit supply device 423 may include a plurality of vaporization fruit first supply devices 4231 and a vaporization fruit second supply device 4232. Here, the vaporization fruit first supply device 4231 and the vaporization fruit second supply device 4232 may be cooling water or engine water of the engine, respectively, and may be configured in parallel or in series with each other.

At this time, the vaporization fruit flows along the vaporization heat circulation line GL for circulating the vaporization heat exchanger 424, the vaporization fruit supply device 423, the vaporization fruit circulation pump 422 and the vaporization fruit storage tank 421. However, each component (evaporation heat exchanger 424, vaporization fruit supply device 423, vaporization fruit circulation pump 422 and vaporization fruit storage tank 421) connected by the vaporization fruit circulation line GL. The order of the present invention may vary in various ways from the drawing.

In addition, in the vaporization fruit circulation line GL, the vaporization fruit branching lines GLb, GBL1, and GBL2 can bypass the vaporization fruit supply device 423 so that the temperature of the vaporization fruit supplied to the vaporization heat exchanger 424 can be adjusted appropriately. ) May be connected, and the vaporization fruit branching lines GLb, GBL1, and GBL2 are branched from the vaporization fruit circulation line GL upstream of the vaporization fruit supply device 423 to be vaporized fruit downstream of the vaporization fruit supply device 423. It can be merged into the circulation line GL.

The vaporization heat exchanger 424 may vaporize the liquefied gas by supplying a heat source to the liquefied gas flowing on the liquefied gas supply line L1 through the circulated vaporized fruit. The configuration type of the vaporization heat exchanger 424 may adopt various configurations of other heat exchangers such as shell & tube, and the like.

The gas supply unit may further include a forced vaporizer 50, a gas-liquid separator 51, and a heater 52. At this time, the forced vaporizer 50, the gas-liquid separator 51, the heater 52 is a low-pressure liquefied gas supply configuration provided in the low-pressure liquefied gas supply line (sixth line (L6)), the boosting and high pressure pump 40 described above , 41), the vaporizer 42 may be a high pressure liquefied gas supply configuration provided in the high pressure liquefied gas supply line (L1).

The low pressure liquefied gas supply configuration may be provided alone or in combination with the high pressure liquefied gas supply configuration, which may be variously changed according to the configuration of the demand destination 20 and is not particularly limited.

The low pressure liquefied gas supply structure and the high pressure liquefied gas supply structure can share the boosting pump 40. That is, at least a portion of the low pressure liquefied gas supply line and the high pressure liquefied gas supply line may be shared and branched downstream of the boosting pump 40.

The forced vaporizer 50 vaporizes the liquefied gas. The forced vaporizer 50 receives the liquefied gas from the liquefied gas storage tank 10 and / or the boosting pump 40 to be heated and vaporized using a heat source, and the heat source used here is as described above in the vaporizer 42. Such as steam, glycol water, sea water, engine exhaust, engine coolant, electricity and the like. The forced vaporizer 50 may also share a heat source with the vaporizer 42.

Forced vaporizer 50 may be connected to the low pressure liquefied gas supply line (L6), it is possible to vaporize the liquefied gas and deliver to the low pressure demand (22). At this time, methane, propane, butane and the like are mixed in the liquefied gas. Methane is vaporized in the liquefied gas heated by the forced vaporizer 50, and propane or butane (hereinafter referred to as heavy carbon) can maintain a liquid phase.

The gas-liquid separator 51 (or may be a heavy carbon separator) separates the heavy carbon remaining in the liquid phase from the vaporized liquefied gas. The demand destination 20 (preferably the low pressure demand destination 22) consuming liquefied gas may reduce the driving efficiency when a large amount of heavy carbon is introduced. Therefore, according to the present invention, the heavy carbon for vaporizing the liquefied gas and maintaining the liquid phase may be separated, thereby improving the quality of the liquefied gas supplied to the demand destination 20, thereby increasing the driving efficiency of the demand destination 20.

In this case, the gas-liquid separator 51 may be referred to as a mist separator, a heavy carbon separator, and the like, and the liquid heavy carbon may be returned to the liquefied gas storage tank 10 or may be delivered to a tank provided separately. Separator 51 may be provided with a heavy carbon return line (not shown) connected to the liquefied gas storage tank (10).

The heater 52 heats the liquefied gas from which the heavy carbon was separated. The forced vaporizer 50 heats the liquefied gas, but the vaporized liquefied gas has a temperature (for example, -100 degrees) for retaining the heavy carbon in the liquid phase, and thus may be less than the temperature required by the customer 20. .

Accordingly, the heater 52 may heat the liquefied gas using various heat sources similar to the forced vaporizer 50, where the heat source may be shared with the forced vaporizer 50 and / or the vaporizer 42.

In order to filter the liquefied gas flowing into the forced vaporizer 50 in the embodiment of the present invention, a strainer (not shown) may be further provided upstream of the forced vaporizer 50. The strainer may be a combination of a plurality of valves and filters.

Although liquefied gas is stored in the liquefied gas storage tank 10, foreign matter may be mixed in the liquefied gas inside the liquefied gas storage tank 10 by various fluids returned from the outside. Therefore, the strainer may filter out the foreign matter mixed in the liquefied gas and allow the pure liquefied gas to be delivered to the forced vaporizer 50.

The forced vaporizer 50 vaporizes the liquefied gas to about -100 degrees, to remove the heavy carbon as described above. At this time, the liquefied gas regulator (not shown) is provided in the forced vaporizer 50, the state (temperature, etc.) of the liquefied gas delivered from the forced vaporizer 50 to the heavy carbon separator and / or heater 52 can be adjusted. .

The gas supply part in this embodiment may further include the H / D compressor 36, the reliquefaction apparatus 37, and the return pump 38.

The H / D compressor 36 may be used for compressing to discharge or incinerate the boil-off gas generated in the liquefied gas storage tank 10 during bunkering, but the type of the compressor is not limited.

The reliquefaction apparatus 37 can re-liquefy excess evaporative gas through a reliquefaction refrigerant, and can return it to the liquefied gas storage tank 10. The reliquefaction apparatus 37 may include a reliquefaction heat exchanger (not shown) and a reliquefaction refrigerant supply device (not shown).

The reliquefaction apparatus 37 supplies cold heat to reliquefy the evaporated gas through the reliquefaction refrigerant supply device, and the refrigerant supplied from the reliquefaction refrigerant supply device is supplied to the reliquefaction heat exchanger through a separate pump (not shown). It can be supplied to supply the cold heat to the boil-off gas to re-liquefy.

The return pump 38 is a liquid to the liquefied gas storage tank 10 through the tenth line (L10) in the gas-liquid separator 35 for separating the evaporated gas re-liquefied in the reliquefaction apparatus 37 into the liquid phase and the gas phase. Can supply

At this time, in the present invention, when the liquid phase is not supplied from the gas-liquid separator 35 to the liquefied gas storage tank 10 (the liquid supply is due to the pressure difference between the gas pressure separator 35 and the internal pressure of the liquefied gas storage tank 10). In the case of being stopped), the liquid phase of the gas-liquid separator 35 may be supplied to the liquefied gas storage tank 10 through the eleventh line L11, which is a bypass line, and bypass valves (not shown) and a return pump 38. Can be.

Specifically, when the liquid evaporated gas stored in the gas-liquid separator 35 is stored at a pressure greater than the internal pressure of the liquefied gas storage tank 10, it may be supplied to the liquefied gas storage tank 10 through the tenth line (L10). When the liquid vaporized gas stored in the first gas-liquid separator 35 is stored at a pressure lower than the internal pressure of the liquefied gas storage tank 10, the liquefied gas supply tank 38 may be driven to drive the liquefied gas storage tank ( 10) can be supplied.

Hereinafter will be described an embodiment of the gas treatment system that can be derived through each configuration described above.

The gas treatment system 1 according to the embodiment of the present invention may further include a component for processing the liquefied gas or the boil-off gas and supplying it to the demand destination 20 through the individual components described above.

Hereinafter, the processing mechanism of the liquefied gas stored in the liquefied gas storage tank 10 and the processing mechanism of the boil-off gas generated in the liquefied gas storage tank 10 will be described in detail.

First, the processing mechanism of the liquefied gas stored in the liquefied gas storage tank 10, the gas processing system 1 according to an embodiment of the present invention, the liquefied gas stored in the liquefied gas storage tank 10, the first line (L1) 1) while supplying to the demand destination 20, using the boosting pump 40 to first pressurize, and filter out impurities of the liquefied gas through a strainer (not shown), and then a) the sixth line L6. Accordingly, it may be supplied to the forced vaporizer 50 or b) to the high pressure pump 41 along the first line L1.

a) The liquefied gas supplied to the forced vaporizer 50 along the sixth line L6 is heated through the forced vaporizer 50 and at least partially vaporized, and the forced vaporized liquefied gas is supplied to the gas-liquid separator 51. The liquid is separated into a gas and a liquid, and the heavy carbon is separated into a liquid and returned to the liquefied gas storage tank 10 while the gas and the liquid are removed, and the gas from which the heavy carbon component has been removed may be supplied to the low pressure demand source 22. .

b) The liquefied gas supplied to the high pressure pump 41 along the first line L1 is pressurized to high pressure by the high pressure pump 41 and vaporized by the vaporizer 42 to be supplied to the high pressure demand 21. Can be.

Looking at the treatment mechanism of the boil-off gas generated in the liquefied gas storage tank 10, the gas treatment system 1 according to an embodiment of the present invention, c) the second boil-off gas generated in the liquefied gas storage tank 10 A multi-stage pressurization using the boil-off gas compressor 30 along the line L2 or d) the third line L3 may be supplied to the demand destination 20.

c) The boil-off gas supplied through the second line L2 may be multi-stage compressed to high pressure by the boil-off gas compressor 30 and supplied to the high-pressure demand destination 21, and the high-pressure through the process of b) described above. The vaporized liquefied gas may also be joined together and supplied to the high pressure demand 21.

d) The boil-off gas supplied through the third line L3 is boil-off gas supplied from the second or third stage of the boil-off gas compressor 30 by the boil-off gas supplied through the second line L2. It may be supplied to the low-pressure demand destination 22, and may be supplied to the low-pressure demand destination 22 by joining with the forced vaporized liquefied gas through the process of a) described above.

In this case, the forced vaporized liquefied gas supplied through the forced vaporizer 50 may be supplied when the fuel consumption of the low pressure demand destination 22 is increased, but is not limited to this example. (The liquefied gas stored in the liquefied gas storage tank 10 has a high composition ratio of heavy carbon, so that the gas is liquefied using the forced vaporizer 50 and the gas-liquid separator 51 to remove the low carbon. ), So that the efficiency of the low pressure demand destination 22 can be increased.

Of course, the evaporated gas generated in the liquefied gas storage tank 10 may be supplied to the gas combustion device 23 and the vent mast 24 as described above, in which case, through a separate line (not shown) It may be supplied to the gas combustion device 23 or to the vent mast 24 via a valve (not shown) provided on the line.

The gas treatment system 1 according to the embodiment of the present invention may include a technique of accumulating the liquefied gas storage tank 10.

The boil-off gas generated in the liquefied gas storage tank 10 of the embodiment of the present invention is supplied to the boil-off gas consumer 20 when the internal pressure of the liquefied gas storage tank 10 is greater than or equal to a preset pressure, and the liquefied gas storage tank 10 When the internal pressure of) is less than the preset pressure, it is accumulated in the liquefied gas storage tank (10). Here, the preset pressure may be 1.06 bar to 1.12 bar, and the boil-off gas consumer 20 may include a gas combustion device 23 and a vent mast 24, and the internal pressure of the liquefied gas storage tank 10 may vary. If the pressure is less than the set pressure, the driving of the engine 20 generating the propulsion force of the vessel (not shown) may be stopped, bunkering (Bunkering), anchoring (Anchoring) or Ballast Voyage.

Specifically, in the embodiment of the present invention, when the internal pressure of the liquefied gas storage tank 10 is less than the preset pressure, the operation of the boil-off gas compressor 30 is stopped, the evaporated gas generated in the liquefied gas storage tank 10 The pressure can be stored as it is inside the liquefied gas storage tank (10).

In the embodiment of the present invention, when the internal pressure of the liquefied gas storage tank 10 is more than the predetermined pressure, more specifically, when the internal pressure of the liquefied gas storage tank 10 is 1.17 bar to 1.20 bar, the liquefied gas storage tank The boil-off gas generated at 10 is pressurized by the boil-off gas compressor 30 to be supplied to the gas-burning apparatus 23 which burns the boil-off gas, and the internal pressure of the liquefied gas storage tank 10 is 1.20 bar to 1.25 bar. In the case, the liquefied gas storage tank 10 is supplied to the vent gas (Vent Mast) to be discharged to the outside, and when the internal pressure of the liquefied gas storage tank 10 is 1.25 bar or more, the liquefied gas storage tank ( Evaporated gas generated in 10) may be supplied to a safety valve (not shown) to be discharged from the inside of the liquefied gas storage tank 10 to the outside through the safety valve.

As described above, in the embodiment of the present invention, by accumulating the boil-off gas generated in the liquefied gas storage tank to within the predetermined pressure, it is necessary to operate the boil-off gas compressor 30 to discharge the boil-off gas to the outside and burn it. There is no power consumption can be reduced, and since the evaporation gas is not emitted to the outside, there is an effect of preventing the waste of the evaporation gas.

The gas treatment system 1 according to the embodiment of the present invention may include a technique for using the H / D compressor 36 in common during bunkering and maintenance of the liquefied gas storage tank 10.

Gas treatment system 1 according to an embodiment of the present invention, the evaporation compressed by the H / D compressor 36, the H / D compressor 36 to pressurize the evaporated gas generated in the liquefied gas storage tank 10 A heater (not shown) for heating the gas and a land storage (Shore) in which the liquefied gas to be supplied to the liquefied gas storage tank 10 when bunkering or the liquefied gas storage tank 10 during the bunkering are temporarily stored. Includes temporary storage (not shown) as a major component.

When the liquefied gas is initially loaded from the outside into the liquefied gas storage tank 10 (including when the liquefied gas is loaded after the maintenance work of the liquefied gas storage tank 10 is completed), that is, when the bunkering, the liquefied gas is used. Considering that is a cryogenic pyrophoric material, a special operation, ie replacement, must be preceded by a general storage tank.

In general, the method of replacing the liquefied gas storage tank 10 removes moisture by supplying dry gas to the liquefied gas storage tank 10, and removes inert gas from the liquefied gas storage tank 10 to eliminate the possibility of fire or explosion. Supply oxygen to remove oxygen. Thereafter, a hydrocarbon gas is supplied into the liquefied gas storage tank 10 to remove the inert gas, and a cool-down process of cooling the liquefied gas storage tank 10 using the liquefied gas is performed. . When the cool down process is completed, the replacement method is completed, and then the liquefied gas such as LNG is supplied into the liquefied gas storage tank 10 to perform the loading operation.

On the contrary, when unloading the liquefied gas stored in the liquefied gas storage tank 10 to Shore (including removing all the liquefied gas before the maintenance work of the liquefied gas storage tank 10), In the process described above, a slightly different operation is performed.

First, all of the liquefied gas stored in the liquefied gas storage tank 10 is discharged to the demand (Shore). At this time, the remaining liquefied gas is present, and undergoes a warm-up step to remove all the remaining liquefied gas. The warm-up step is to increase the internal temperature of the liquefied gas storage tank 10 by compressing the evaporated gas generated in the liquefied gas storage tank 10 with a compressor and then heating it with a separate heater to return to the liquefied gas storage tank 10 again. Allow all remaining liquefied gas to vaporize. After the warm-up step, an inert gas is supplied to remove all the boil-off gas remaining in the liquefied gas storage tank 10 and a dry gas is added to dry the interior, and then oxygen is supplied to supply air to the interior. By going through the above process, the unloading process of the liquefied gas storage tank 10 is completed, the worker for carrying out the maintenance work and the like can be drawn in.

Here, during the liquefied gas loading process (when bunkering), even when the liquefied gas storage tank 10 is cooled down, a large amount of boil-off gas is generated when the liquefied gas is shipped, and the internal pressure of the liquefied gas storage tank 10 may increase. There is a concern that a compressor is used to discharge the generated boil-off gas to the Shore.

In the liquefied gas unloading process, the compressor is used in the process of compressing the boil-off gas in order to increase the internal temperature of the liquefied gas storage tank 10 in the warm-up step.

The H / D compressor 36 may implement both the compression process used during the liquefied gas loading process and the compression process used during the liquefied gas unloading process as described above.

That is, the H / D compressor 36 pressurizes the boil-off gas generated during bunkering and supplies it to the shore demand site, or warms up when the liquefied gas is unloaded (before maintenance of the liquefied gas storage tank 10). In step liquefied gas storage tank 10 to pressurize the remaining evaporated gas back to the liquefied gas storage tank 10 may be circulated to the liquefied gas storage tank (10).

In detail, the H / D compressor 36 may receive the boil-off gas generated from the liquefied gas storage tank 10 through the seventh line L7 and compress the compressed gas to be supplied to the land demand site Shore. When the liquefied gas is unloaded (when the liquefied gas storage tank 10 is maintained before maintenance), the remaining evaporated gas in the liquefied gas storage tank 10 is compressed and heated by the heater 361, and then the eighth line (L8) and The liquefied gas storage tank 10 is returned to the liquefied gas storage tank 10 via the twelfth line L12, and the liquefied gas storage tank 10, the H / D compressor 36, the heater 361, and the liquefied gas storage tank 10 are returned. Can be cycled in order. As a result, all the liquefied gas stored in the liquefied gas storage tank 10 may be vaporized, and all of the liquefied gas may be discharged to the outside of the liquefied gas storage tank 10.

In this case, the H / D compressor 36 may be a high duty compressor.

That is, the H / D compressor 36 is used to compress the evaporated gas generated during bunkering and discharge it to the land demand site (Shore), and at the same time when the liquefied gas is unloaded (before the maintenance start of the liquefied gas storage tank 10). In this case, in order to vaporize all the remaining liquefied gas stored in the liquefied gas storage tank 10, it may be used to pressurize the liquefied gas storage tank 10 to circulate by raising the temperature of the remaining boiled gas.

Thus, in the embodiment of the present invention, since the H / D compressor 36 can be used in common during bunkering, liquefied gas unloading or liquefied gas storage tank 10 maintenance, the construction cost of the compressor is reduced As a result, the construction space of the system is reduced, thereby maximizing the space used in the ship.

The gas treatment system 1 according to the embodiment of the present invention further includes a pressure reducing valve 341 together with the reliquefaction apparatus 37 to improve the reliquefaction rate, and the return pump according to the internal pressure of the gas-liquid separator 35 ( And technology for bypassing 35) and sharing a line through which the boil-off gas is supplied to the GCU 23 and the reliquefaction apparatus 37.

Gas processing system 1 according to an embodiment of the present invention, the boil-off gas compressor 30, the boil-off gas compressed in the boil-off gas compressor 30, the boil-off gas compressor 30 to pressurize the boil-off gas generated in the liquefied gas storage tank 10 Reliquefaction apparatus 37 for liquefying through a refrigerant, a first pressure reducing valve 341 for decompressing or expanding the boil-off gas compressed in the boil-off gas compressor 30, at least partially liquefied boil-off gas through the re-liquefaction Mainly includes a gas-liquid separator (35) for separating the vaporized and liquefied boiled gas through the second pressure reducing valve 342 and the second pressure-reducing valve 342 to maintain the secondary pressure, and gas phase and liquid phase do.

Here, the reliquefaction apparatus 37 may liquefy the evaporated gas branched at the intermediate end of the evaporative gas compressor 30 to a low pressure (13 bar to 15 bar) through a refrigerant, and more specifically, the evaporative gas compressor ( The boil-off gas branched at the intermediate stage of 30) and compressed to low pressure (13 bar to 15 bar) is first reduced in pressure to 7 bar to 8 bar through the first pressure reducing valve 341, and then cooled through the reliquefaction apparatus 37, The cooled boil-off gas may be secondly reduced to 5 bar to 6 bar through the second pressure reducing valve 342.

As described above, in the exemplary embodiment of the present invention, a pressure reducing valve 342 may be further provided at the rear end of the reliquefaction apparatus 37 to further improve the reliquefaction efficiency as compared with the related art.

In addition, the gas-liquid separator 35 supplies the separated gas phase to the gas combustion device 23 that consumes flash gas through the heater 33, and the separated liquid phase is supplied to the liquefied gas storage tank 10. Can be returned. In the embodiment of the present invention, the return line (L10; tenth line) connecting the gas-liquid separator 35 and the liquefied gas storage tank 10, the bypass line (L11) is bypassed on the return line (L10) 11 line), a pump 38 (return pump) and a first pressure reducing valve 341 provided on the bypass line L11 to return the liquid liquefied gas stored in the gas-liquid separator 35 to the liquefied gas storage tank 10. ) May further include a branch line (not shown) which is branched between the reliquefaction apparatus 37 and supplied to the gas combustion apparatus 23.

Specifically, the liquefied gas of the liquid phase stored in the gas-liquid separator 35, when the internal pressure of the gas-liquid separator 35 is equal to or higher than the preset pressure value, to the liquefied gas storage tank 10 through the return line (L10; tenth line). When the internal pressure of the gas-liquid separator 35 is less than the preset pressure value, the return pump 38 may be driven to be supplied to the liquefied gas storage tank 10 through the bypass line L11 (the eleventh line). have.

That is, the gas-liquid separator 35 stores the second reduced pressure evaporated gas at 5 bar to 6 bar through the second pressure reducing valve 342, so that the reduced pressure of the liquid vaporized gas is larger than the internal pressure of the liquefied gas storage tank 10. Since the internal pressure of the gas-liquid separator 35 is greater than or equal to a predetermined pressure value, since the pressure may be naturally supplied through the pressure gradient, the return pump 38 may be supplied to the liquefied gas storage tank 10 through the return line L10. It is effective to prevent the driving power consumption and to implement a return to the stable liquefied gas storage tank (10).

In addition, the branch line is branched at the middle end of the boil-off gas compressor 30 and compressed at a low pressure when the supply amount of the boil-off gas is lower than the preset supply amount. When at least a portion of the boil-off gas is supplied to the gas combustion device 23 and the supply amount of the boil-off gas branched at the middle end of the boil-off gas compressor 30 and compressed at low pressure is less than the preset supply amount, the boil-off gas compressor 30 All of the boil-off gas branched at the intermediate stage of the low pressure can be supplied to the reliquefaction apparatus 37.

That is, the first pressure reducing valve 341 and the second pressure reducing valve 342 are provided on the fourth line L4 together with the side stream line of the separate boil-off gas compressor 30 in addition to the fourth line L4. It is not necessary to minimize the branching line of the boil-off gas compressor 301, thereby improving the driving reliability of the system. (The more the side stream line of the evaporating gas compressor 30, the higher the driving efficiency. Falling)

Here, the predetermined pressure value is 5bar to 6bar, the reliquefaction apparatus 37 may use a refrigerant as nitrogen, and the second pressure reducing valve 342 may be a Joule-Thompson valve.

The gas treatment system 1 according to the embodiment of the present invention reduces the delivery pressure of the boosting pump 40 when supplying the liquefied gas to the high pressure demand destination 21 and the technology for supplying the low pressure demand destination 22 without additional pressure reduction. Technology may be included.

Gas processing system 1 according to an embodiment of the present invention, the boosting pump 40 for pressurizing the liquefied gas stored in the liquefied gas storage tank 10, the liquefied gas primary pressurized from the boosting pump 40 High-pressure pump 41 to be supplied and pressurized secondly The vaporizer 42 for receiving and vaporizing the second pressurized liquefied gas from the high-pressure pump 41, the high-pressure liquefied gas or evaporated gas compressor 30 vaporized from the vaporizer 42 High pressure demand destination (21) for receiving and consuming the pressurized boil off gas, low pressure demand destination (22) for branching from the intermediate stage of the boil-off gas compressor (30) and receiving pressurized boil-off gas at low pressure, liquefied gas storage tank It is provided between the forced vaporizer 50 and the forced vaporizer 50 and the low pressure demand destination 22 to receive the liquefied gas stored in the (10) forcibly vaporized and received the forced vaporized liquefied gas from the forced vaporizer (50) Separator in liquid phase And a separator 51 as an essential component.

The boosting pump 40 is configured to pressurize the liquefied gas stored in the liquefied gas storage tank 10 to the high pressure pump 41 or the forced vaporizer 50 so as to supply the high pressure pump 41 through the boosting pump 40. ) And the use of the pump to feed to the forced vaporizer (50) can be shared.

Here, the forced vaporizer 50, the liquefied gas stored in the liquefied gas storage tank 10 is supplied from the boosting pump 40 in the first pressurized state to be vaporized and then supplied to the low pressure demand destination 22 to low pressure without a separate pressure The fuel can be supplied to the demand destination 22. As a result, in the present embodiment, it is possible to omit the provision of the pressure reducing valve at the inlet end of the low pressure demand destination 22.

In addition, the forced vaporizer 50, the liquefied gas stored in the liquefied gas storage tank 10 is supplied from the boosting pump 40 in a first pressurized state to vaporize and then to be supplied to the front end of the boil-off gas compressor 30 Can be. In the present embodiment, the required pressure of the demand destination 20 is matched by the boil-off gas compressor 30, so that the output pressure of the boosting pump 40 may be lowered. Of course, even in this case, the liquefied gas supplied to the forced vaporizer 50 may be supplied through the boosting pump 40 to supply the liquefied gas to the high pressure pump 41.

As such, by sharing the use of the pump to supply the high pressure pump 41 and the forced vaporizer 50 through the boosting pump 40, there is an effect that can reduce the construction cost of the pump 40, forced vaporizer 50 By supplying the forced vaporized boil-off gas through) to the front end of the boil-off gas compressor 30, the liquefied gas delivery pressure in the liquefied gas storage tank 10 is lowered, thereby reducing the driving power of the pump 40.

Gas treatment system 1 according to an embodiment of the present invention, the return line (L10) of the gas-liquid separator 35 provided in the rear end of the reliquefaction apparatus 37, the cool down circulation line (L13) of the high pressure pump (42). It may include a technique for sharing at least one of each of the return line (not shown) of the gas-liquid separator 51 provided at the rear end of the forced vaporizer (50).

Gas treatment system 1 according to an embodiment of the present invention, the re-liquefaction apparatus 37 for reliquefaction of the boil-off gas compressed by the boil-off gas compressor 30, the gaseous liquefied boil-off gas in the re-liquefaction apparatus 37 Gaseous liquefied gas vaporized from the gas-liquid separator 35 for separating the liquid into a liquid phase, a high pressure pump 42 for pressurizing the liquefied gas stored in the liquefied gas storage tank 10, and a forced vaporizer 50 forcibly vaporizing the liquefied gas. Cooling circulation line (L13; line 13), gas-liquid separator connected to the liquefied gas storage tank 10 from the high-pressure pump 42 at the time of cooling down the gas-liquid separator 51 to separate the liquid and liquid Returning the liquid phase of the gas-liquid separator 35 to the liquefied gas storage tank 10 and the return line (L10; line 10) of the gas-liquid separator 35 to return to the liquefied gas storage tank 10 The return line (not shown) of the gas-liquid separator 51 is included as a main structure.

In the embodiment of the present invention, when the high pressure pump 41 cools down the line L13 to return to the liquefied gas storage tank 10 from the high pressure pump 41, the liquid phase of the gas-liquid separator 35 to the liquefied gas storage tank ( At least one line L10 returning to 10) and a line returning the liquid phase of the gas-liquid separator 51 to the liquefied gas storage tank 10 may be shared.

As such, the cool down circulation line L13 of the high pressure pump 41, the return line L11 of the gas-liquid separator 35, and the return line of the gas-liquid separator 51 are shared at least one, thereby simplifying the structure of the return line. The driving reliability of the system is improved, and the return can be stably implemented, and the return line is shared so that the cool down can be performed in advance, so that the liquid evaporated gas returns to the liquefied gas storage tank 10 and recovers. There is an effect that the liquefaction does not occur, that is, there is an effect that the actual reliquefaction efficiency is increased.

For example, in the embodiment of the present invention, only the cool down circulation line L13 of the high pressure pump 41 and the return line of the gas-liquid separator 35 may be shared.

When the high pressure demand destination 21 is driven through the liquefied gas and the evaporated gas is reliquefied by the reliquefaction apparatus 37 at the same time, the discharge pressure of the gas-liquid separator 35, that is, the return line L10 The pressure is about 5 ~ 6bar and the cool down circulation line (L13) of the high-pressure pump 41 corresponds to about 9bar, the return line (L10) in the case of the back pressure may be a problem that flow back to the gas-liquid separator (35).

However, in the embodiment of the present invention, since the case where the high pressure demand destination 21 is driven through the liquefied gas and the case where the evaporated gas is reliquefied by the reliquefaction apparatus 37 do not occur at the same time, a high pressure pump ( Only the return line of the cooldown circulation line L13 and the gas-liquid separator 35 of 41 can be shared to prevent back pressure on the shared line and to effectively share the return line. (The reliquefaction apparatus 37 is driven. If the evaporation gas is left in this case, in this case, since the evaporation gas is supplied to the high pressure demand destination 21 through the evaporation gas compressor 30, the liquefied gas is supplied to the high pressure demand destination through the high pressure pump 41 ( 21 does not need to be sent to, so that the high pressure pump 41 is not driven.)

As another example, in the embodiment of the present invention, the cooldown circulation line L13 of the high pressure pump 41 and the return line of the gas-liquid separator 51 are shared only when both the high pressure demand destination 21 and the low pressure demand destination 22 are driven. Can be.

The forced vaporizer 50 operates only when the low pressure demand destination 22 is driven, and the high pressure pump 41 operates only when the high pressure demand destination 21 is driven, so that the high pressure and low

pressure demand destinations

21 and 22 are operated. Only when both are operated, the cool down circulation line L13 of the high pressure pump 41 and the return line of the gas-liquid separator 51 may be shared.

As a result, the return line of the gas-liquid separator 51 is cooled in advance by the cool down of the high-pressure pump 41, and the liquid phase returned from the gas-liquid separator 51 to the liquefied gas storage tank 10 is not regasified. The internal pressure of (10) can be managed efficiently. Of course, at this time, the return line of the gas-liquid separator 51 and the cooldown circulation line L13 of the high pressure pump 41 are different from each other so that the problem of back pressure does not occur. It is driven only at the beginning of supply to the high pressure demand 21, and the return line of the gas-liquid separator 51 is continuously driven while being supplied to the low pressure demand 22.)

Gas processing system 1 according to an embodiment of the present invention, by connecting the front end of the forced vaporizer 50 with the return line of the gas-liquid separator 51 to simplify the cooling down of the return line of the gas-liquid separator 51 It may include.

Gas processing system 1 according to an embodiment of the present invention, the gas-liquid separator 51, the gas-liquid separator 51 for separating the forced vaporized liquefied gas into the gaseous phase and the liquid phase from the forced vaporizer 50 forcibly vaporizing the liquefied gas Return line of the gas-liquid separator 51 for returning the liquid phase of the gas to the liquefied gas storage tank 10, and a bypass line connecting the front end of the forced vaporizer 50 and the return line of the gas-liquid separator 51 (not shown) It is included in the main configuration.

In the embodiment of the present invention, a bypass line connecting the front end of the forced vaporizer 50 and the return line of the gas-liquid separator 51, the return line of the forced vaporizer 50 and the return of the gas-liquid separator 51 You can share lines together.

Through this, the bypass line of the forced vaporizer 50 is connected to the return line of the gas-liquid separator 51, not the front end of the gas-liquid separator 51, and the bypass function of the forced vaporizer 50 and the return line of the gas-liquid separator 51 The cool down function can be shared, so that the cool down of the gas-liquid separator 51 is simplified and optimized.

The gas treatment system 1 according to the embodiment of the present invention may include a technique of supplying engine coolant and steam in parallel and in series to supply a heat source to glycol water used in the vaporizer 42.

Hereinafter, a description will be given with reference to FIGS. 2A to 2C. However, first, the vaporizer first and

second embodiments

42a and 42b will be described together.

2A and 2B are conceptual views of a vaporization system in the gas treatment system of the present invention.

Vaporizers of the gas treatment system 1 according to the embodiment of the present invention, the first and

second embodiments

42a and 42b may include a vaporizer 424 for vaporizing liquefied gas stored in the liquefied gas storage tank 10 through a vaporized fruit. Vaporized heat exchanger), a first heat exchanger (4231; vaporized fruit first supply device) for exchanging the vaporized heat and the engine coolant, a second heat exchanger (4232; second vaporized heat supply device) for supplying heat to the vaporized heat, and vaporization A circulation pump 422 which circulates to supply fruit to the vaporizer 424.

Specifically, in the vaporizer first and

second embodiments

42a and 42b of the gas processing system 1 according to the embodiment of the present invention, the vaporization fruit first supply device 4231 and the vaporization fruit second supply device 4232 ) May supply a heat source to the vaporized fruit in the order of the vaporized fruit first supply device (4231), the vaporized fruit second supply device (4232), more specifically, the circulation pump 422, the vaporized fruit first supply device ( 4231), the vaporization fruit second supply device 4232 may be connected in series, or the vaporization fruit first supply device 4231, the circulation pump 422, and the vaporization fruit second supply device 4232 may be connected in series.

Here, the vaporization fruit first supply device 4231 and the vaporization fruit second supply device 4232 have a vaporization fruit first supply device 4231, and the vaporization fruit second supply device 4232 be a Shell & Tube method. The types of heat exchangers may be different from each other. Of course, both heat exchangers can be used in the same type, either plate or shell & tube. In addition, the vaporization fruit second supply device 4232 may use steam or seawater as a heat source supplied to the vaporization fruit.

In the vaporizer first and

second embodiments

42a and 42b of the gas treatment system 1 according to the embodiment of the present invention, the first and second ends of the vaporization fruit first supply device 4231 are connected to supply the vaporization fruit first. First bypass line (GBL1; vaporization fruit first branch line) for bypassing the vaporized fruit that has passed through the device (4231) from the rear end of the vaporization fruit first supply device (4231) to the front end, and the vaporized fruit second supply device (4232) A second bypass line (GBL2; vaporizing fruit agent) which connects the front end and the rear end of the c) to bypass the vaporizing fruit passing through the vaporizing fruit second supply device 4232 to the front end of the vaporizing fruit second supply device 4232. The control unit 902 may control the second branch line, the first bypass line GBL1 or the second bypass line GBL2, and the vaporization fruit storage tank 421 may store the vaporization fruit.

When the vaporization fruit supplied to the vaporizer 424 is equal to or lower than the preset temperature value, the controller 902 may drive the vaporization fruit first branch line GBL1 or the vaporization fruit second branch line GBL2 to reheat the vaporization fruit. Can be. Here, the preset temperature value may be an image from 85 degrees to an image of 95 degrees, and the vaporized fruit second supply device 4232 may be supplied with a heat source depending on the heat source supply capability of the vaporized fruit first supply device 4231.

Referring to a process in which the vaporized fruit is heated / cooled circulated in the first embodiment 42a of the gas treatment system according to an embodiment of the present invention, the vaporized fruit stored in the vaporized fruit storage tank 421 is circulated in the vaporized fruit. It is circulated through the pump 422 and heated by the engine cooling water (jacket cooling water) by the vaporization fruit first supply device 4231 to be heated up to a maximum image 70 degrees, after which the vaporization fruit second supply device 4232 To be heated through steam or seawater to be heated to about 85-95 degrees (preferably 90 degrees), then supplied to the vaporization heat exchanger 424 and then flowing through the first line L1. The liquefied gas of 130 degrees may be heated to an image of 35 to 55 degrees, and the vaporized refrigerant may be cooled to an image of 50 to 90 degrees.

In this case, since the engine coolant is supplied by the vaporization fruit first supply device 4231 and the amount of the engine coolant is variable according to the driving of the engine when heated, the heat source supply amount of the engine coolant may be reduced when the engine coolant is driven at a low speed so that the vaporization fruit second supply device is provided. 4232 is dependent on the vaporization fruit first supply device 4231 and may be heated. This may be implemented by driving the above-described control unit 902, the control unit 902, the temperature information of the liquefied gas or vaporized fruit from the first temperature measuring device 921 and the second temperature measuring device 922 Wired or wireless transmission may be performed, and based on this, the vaporization fruit may be heated by driving the first bypass line GBL1 or the second bypass line GBL2 according to the above-described situation.

In the second embodiment 42b of the gas treatment system 1 according to the embodiment of the present invention, a process of heating / cooling the vaporized fruit is described. The vaporized fruit first supply device 4231 and the vaporized fruit circulation pump are described. Since only the order of 422 has been changed, other than the same as described in the first embodiment of the carburetor 42a described above, it will be replaced.

The carburetor third embodiment 42c will now be described.

The vaporizer | carburetor 3rd Example 42c of the gas processing system 1 which concerns on embodiment of this invention is the vaporization heat exchanger 424, the vaporization heat exchanger 1st supply 4231, the vaporization heat exchanger 2432, A heater 4233 (additional vaporization heater) and a vaporization fruit, which are provided at the rear end of the circulation pump 422 and the vaporization fruit first supply device 4231, and further heat the vaporization fruit heated in the vaporization fruit first supply device 4231. A bypass line (GBL4) provided at the rear end of the first supply device 4231 to supply the vaporized fruit heated in the first vaporization device 14231 to the front end of the second vaporized fruit supply 4423; Third branch line).

In the vaporization fruit first supply device 4231 and the vaporization fruit second supply device 4232, the vaporization fruit first supply device 4231 and the vaporization fruit second supply device 4232 are connected in parallel to each other. The supply device 4231 first heats the vaporized fruit, and the vaporized fruit second supply device 4232 can secondly heat the vaporized fruit, and the vaporized fruit first supply device 4231 and the vaporized fruit second supply device 4232 ) May be disposed at the rear end of the circulation pump 422.

Specifically, the vaporized fruit heated by the vaporization fruit first supply device 4231 is heated by the heater 4333 when the temperature at the rear end of the vaporization fruit first supply device 4231 is equal to or less than the preset temperature. Alternatively, it may be supplied to the front end of the vaporization fruit second supply device 4232 through the bypass line (GBL4).

Here, the vaporization fruit first supply device 4231 is a plate type, and the vaporization fruit second supply device 4232 may be a shell & tube method, and the types of the two heat exchangers may be different. Can also be used in the same kind. The vaporization fruit second supply device 4232 may use steam or seawater as a heat source supplied to the vaporization fruit.

Referring to the process in which the vaporized fruit is heated / cooled circulated in the third embodiment 42c of the gas treatment system 1 according to the embodiment of the present invention, the vaporized fruit stored in the vaporized fruit storage tank 421 is vaporized. It is circulated through the fruit circulation pump 422 and is heated by the engine cooling water (jacket cooling water) by the vaporization fruit first supply device 4231 may be heated up to 90 degrees.

However, since the amount of the engine coolant varies depending on the driving of the engine, it may be difficult to supply a constant heat source to the vaporization heat exchanger 424 at all times due to a severe temperature change. In order to prevent this, the present invention may further include a vaporization fruit additional heater 4333. In the present invention, when the engine is driven at a low speed and the amount of heat source supplied to the engine coolant is reduced, the engine can be heated up to 90 degrees by reheating through the additional vaporization heater 4233. Thereafter, the liquefied gas of minus 130 degrees supplied to the vaporization heat exchanger 424 and flowing through the first line L1 may be heated to images 35 to 55 degrees, and the vaporization refrigerant may be cooled to images 50 at 90 degrees. .

Here, the vaporization fruit second supply device 4232 may vary depending on the vaporization fruit first supply device 4231 and may be heated. This may be implemented by driving the above-described control unit 902, the control unit 902, the temperature information of the liquefied gas or vaporized fruit from the first temperature measuring device 921 and the second temperature measuring device 922 Wired or wireless transmission may be performed, and based on this, the vaporization fruit may be heated by driving the first bypass line GBL1 or the second bypass line GBL2 according to the above-described situation.

In addition, when the engine supply is stopped for a long time and the supply of the engine cooling water becomes very small, and the amount of heating is not enough even with the additional vaporization fruit heater 4233, the vaporization fruit is the third vaporization fruit. Since the vaporized fruit circulation line GL is not supplied to the branch line GBL3, the vaporized fruit may be heated up to 90 degrees.

In the third embodiment 42c of the carburetor according to an embodiment of the present invention, since the amount of engine coolant varies according to the driving of the engine, when the heat source supply amount of the engine coolant is reduced at low speed, the fourth branch line (GBL4) The vaporization fruit may be bypassed to the second supply device 4232 to heat up to 90 degrees by the vaporization fruit second supply device 4232.

In this way, through the parallel or series connection of the above-described vaporized fruit supply device, the steam flow rate is reduced due to the engine cooling water through the heating technology of the vaporized fruit, and thus the boiler operation can be reduced, thereby reducing the fuel consumption, and the serial or parallel connection As a result, the driving reliability of the vaporizer 42 is improved.

The gas treatment system 1 according to the exemplary embodiment of the present invention may include a technique for implementing liquefied gas and boiled gas through parallel driving according to the internal pressure of the liquefied gas storage tank 10.

Gas processing system 1 according to an embodiment of the present invention, the liquefied gas processing device for supplying to the demand by pressing / heating the liquefied gas stored in the boil-off gas compressor 30, the liquefied gas storage tank 10 provided in parallel (40, 41, 42), the reliquefaction apparatus 37 for reliquefaction of the boil-off gas compressed by the boil-off gas compressor 30, the rear end of the re-liquefaction apparatus 37 is liquefied by the reliquefaction apparatus 37 The second pressure reducing valve 342 for decompressing or expanding the evaporated gas, the gas combustion device 23 for consuming the boiled gas, and the forced vaporizer 50 for forcibly vaporizing the liquefied gas stored in the liquefied gas storage tank 10 are mainly used. Include in the configuration.

Here, the liquefied gas processing apparatus (40, 41, 42) receives the pressurized liquefied gas from the boosting pump 40, the boosting pump 40 for the primary pressurization of the liquefied gas stored in the liquefied gas storage tank 10 It includes a high-pressure pump 41 for secondary pressure and a vaporizer 42 for receiving the vaporized pressurized liquefied gas from the high-pressure pump 41 to vaporize, the boil-off gas compressor 30 is provided in parallel to the first boil-off gas It may be provided as a compressor (not shown) and a second boil-off gas compressor (not shown).

Hereinafter, the first parallel driving of the gas treatment system 1 according to the internal pressure of the liquefied gas storage tank 10 will be described.

The first preset pressure is the internal pressure of the liquefied gas storage tank 10 when the BOG amount is 75 to 85% in the liquefied gas storage tank 10, and the second preset pressure is the first preset pressure. Greater than and less than 1,12 bar, the third preset pressure is less than the first preset pressure and greater than 1.06 bar, and the fourth preset pressure may be less than the third preset pressure and greater than 1.03 bar.

First, the first boil-off gas compressor is basically driven. When the internal pressure of the liquefied gas storage tank 10 is greater than or equal to the first predetermined pressure, the second boil-off gas compressor is further driven, and when the internal pressure of the liquefied gas storage tank 10 is less than the first predetermined pressure, the liquefied gas processing apparatus. 40, 41, 42 are further driven.

The boil-off gas generated in the liquefied gas storage tank 10 may be supplied to the reliquefaction device 37 or the gas combustion device 23 when the internal pressure of the liquefied gas storage tank 10 is equal to or greater than the second preset pressure. In addition, when the internal pressure of the liquefied gas storage tank 10 is greater than or equal to the second preset pressure, and the fuel required amount of the demand destination 20 is greater than or equal to the preset required amount, the liquefied

gas processing apparatus

40, 41, 42 may be further driven. have.

In addition, when the internal pressure of the liquefied gas storage tank 10 is less than the third preset pressure, driving of the first boil-off gas compressor may be stopped, and the internal pressure of the liquefied gas storage tank 10 is less than the fourth preset pressure. Forcibly vaporizing the liquefied gas stored in the liquefied gas storage tank 10 through the forced vaporizer 50, and returning the forced liquefied gas back to the liquefied gas storage tank 10, the internal pressure of the liquefied gas storage tank 10 Can be raised.

At this time, in the embodiment of the present invention, a pressure measuring device (not shown) for measuring the internal pressure of the control unit (not shown) and the liquefied gas storage tank 10 and a fuel requirement measuring device for measuring the fuel required amount of the demand destination 20 ( (Not shown) and the control unit receives information from the pressure measuring device and the fuel requirement measuring device by wire or wirelessly so that the internal pressure of the liquefied gas storage tank 10 described above is the first to fourth groups. The liquefied

gas treating apparatuses

40, 41, 42 and the boil-off gas compressor 30 may be controlled with respect to the fluctuation according to the set pressure.

As described above, in the embodiment of the present invention, by driving the boil-off gas compressor 30 and the liquefied

gas processing apparatus

40, 41, 42 in parallel so that the demand source 20 can be driven flexibly without supply of oil. The system construction cost is reduced.

Gas treatment system 1 according to an embodiment of the present invention, when the internal pressure of the liquefied gas storage tank 10 is low pressure to implement the processing of the liquefied gas, boil-off gas and oil according to the flow of the internal pressure through a parallel drive Technology may be included.

Gas treatment system 1 according to an embodiment of the present invention, the boil-off gas compressor 30, the reliquefaction apparatus 37, the liquefied gas treatment apparatus (40, 41, 42), the second pressure reducing valve 342 and oil An oil treatment device (not shown) for supplying oil stored in a storage tank (not shown) to the demand destination 20 is included as a main configuration.

Hereinafter, the second parallel driving of the gas treatment system 1 according to the internal pressure of the liquefied gas storage tank 10 will be described.

The boil-off gas compressor 30 is basically driven at the first preset pressure, and when the amount of boil-off gas generated in the liquefied gas storage tank 10 is larger than the amount of fuel required by the demand source 20, the re-liquefaction device 37 is turned on. Further operation, if the amount of boil-off gas generated in the liquefied gas storage tank 10 is less than the fuel required amount of the demand source 20, the liquefied gas treatment apparatus (40, 41, 42) and the oil treatment apparatus can be further operated. . Preferably, the liquefied

gas treatment apparatuses

40, 41, and 42 are first operated, and the oil treatment apparatus can be lane-operated.

Here, the first preset pressure may be an internal pressure of the liquefied gas storage tank 10 when the BOR (Boiled Off Rate) in the liquefied gas storage tank 10 is 75 to 85%, or may be 1.06 bar to 1.12 bar. .

At this time, in the embodiment of the present invention, the control unit receives information from the pressure measuring device and the fuel requirement measuring device by wire or wirelessly, and the internal pressure of the liquefied gas storage tank 10 described above is changed according to the first preset pressure. It is possible to control the liquefied gas treatment device (40, 41, 42), the boil-off gas compressor (30) and the oil treatment device.

As described above, in the embodiment of the present invention, the boil-off gas compressor 30, the liquefied

gas processing devices

40, 41, and 42 and the oil processing device are driven in parallel to satisfy the homeostasis of the fuel supply of the system. This has the effect of being improved.

Gas treatment system 1 according to an embodiment of the present invention, when the internal pressure of the liquefied gas storage tank 10 is a high pressure to implement the treatment of liquefied gas, boil-off gas and oil according to the flow of the internal pressure through a parallel drive Technology may be included.

The gas treatment system 1 according to the embodiment of the present invention includes, as main components, an evaporative gas compressor 30 and a reliquefaction apparatus 37 provided in parallel. Here, the boil-off gas compressor 30 may be provided in parallel and include a first boil-off gas compressor (not shown) and a second boil-off gas compressor (not shown).

Hereinafter, the control operation of the gas treatment system 1 according to the internal pressure of the liquefied gas storage tank 10 will be described.

When the internal pressure of the liquefied gas storage tank 10 is greater than or equal to a predetermined pressure, the first boil-off gas compressor is operated to supply to the demand destination 20, and the liquefied gas storage tank 10 generated by the liquefied gas storage tank 10 is produced. If the amount of boil-off gas is larger, the reliquefaction apparatus 37 may be further operated or the second boil-off gas compressor may be further operated. Preferably. By first operating the second boil-off gas compressor and supplying it to the demand destination 20, the ship's ship speed can be increased, and the reliquefaction apparatus 37 can be lane-operated. In this case, the preset pressure may be 1.11 bar to 1.13 bar.

As described above, in the embodiment of the present invention, the boil-off gas compressor 30 is operated in parallel and the re-liquefaction device 37 is further driven to efficiently process the boil-off gas continuously discharged from the liquefied gas storage tank 10 to store the liquefied gas. There is an effect that can stabilize the internal pressure of the tank (10).

Although the present invention has been described in detail through specific examples, it is intended to describe the present invention in detail, and the present invention is not limited thereto, and should be understood by those skilled in the art within the technical spirit of the present invention. It is obvious that the modifications and improvements are 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 apparent from the appended claims.

Claims

A first line connecting the liquefied gas storage tank and the high pressure gas injection engine;

A second line branching from the first line;

A reliquefaction apparatus provided on the second line and configured to heat-exchange the remaining evaporated gas not supplied to the high-pressure gas injection engine with a refrigerant; And

And a expansion valve provided downstream of the reliquefaction apparatus, the expansion valve configured to expand the boil-off gas.
The method of claim 1,

An evaporative gas compressor provided on the first line; And

And a pressure reducing valve provided upstream of the reliquefaction apparatus on the second line and configured to reduce the boil-off gas compressed by the boil-off gas compressor and branched from the boil-off gas compressor.
The method of claim 2, wherein the second line,

And a gas treatment system branching at an intermediate end of the boil-off compressor.
The method of claim 3, wherein the boil-off gas branched at the intermediate stage of the boil-off gas compressor and compressed at low pressure,

Primary pressure reduction to 7bar to 8bar through the pressure reducing valve,

Cooled through the reliquefaction apparatus,

A vessel comprising a gas treatment system characterized in that the secondary pressure is reduced to 5bar to 6bar through the expansion valve.
The method of claim 4, wherein

A third line branched between the pressure reducing valve and the reliquefaction device and connected to a gas combustion device (GCU),

The third line,

When the liquefied gas storage tank is in the normal pressure range which is the internal pressure when it is safe, when the internal pressure of the liquefied gas storage tank is higher than the normal pressure range, the boil-off gas branched at the intermediate stage of the boil-off gas compressor and compressed to low pressure A vessel comprising a gas processing system, characterized in that to supply at least a portion of the gas combustion device.
The method of claim 1,

And a gas-liquid separator for separating the re-liquefied boil-off gas through the expansion valve into a gas phase and a liquid phase.
The gas-liquid separator of claim 6,

And a separated gaseous phase is supplied to a gas combustion unit (GCU) consuming a flash gas, and the separated liquid phase is returned to the liquefied gas storage tank.
The method of claim 6,

A fourth line connecting the gas-liquid separator and the liquefied gas storage tank;

A pump provided on the fourth line to return the liquid liquefied gas stored in the gas-liquid separator to the liquefied gas storage tank; And

And a fifth line bypassing said pump.
The method of claim 8, wherein the liquefied gas of the liquid phase stored in the gas-liquid separator

When the internal pressure of the gas-liquid separator is equal to or greater than a predetermined pressure value, the pump is bypassed to the pump through the fifth line and supplied to the liquefied gas storage tank.

When the internal pressure of the gas-liquid separator is less than the predetermined pressure value, the vessel comprising a gas treatment system characterized in that for supplying to the liquefied gas storage tank through the pump.
The method of claim 9, wherein the predetermined pressure value,

Ship comprising a gas treatment system, characterized in that 5bar to 6bar.
The method of claim 1,

The reliquefaction apparatus uses a nitrogen refrigerant or a mixed refrigerant as a refrigerant,

And the boil-off gas first liquefier is a Joule-Thomson valve.
The method of claim 1,

And a sixth line branched from the first line and connected to the heterogeneous fuel power generation engine.

The second line is branched on the sixth line.