KR20190060743A - method and Apparatus for transferring liquid cargo - Google Patents

Abstract

The present invention provides an apparatus for transferring liquid cargo. The apparatus for transferring liquid cargo of the present invention includes: a liquid cargo transfer line connected to a liquid cargo storage tank; a drum connected to the liquid cargo transfer line and providing a space in which liquid cargo is stored; a pressurizing unit pressurizing the liquid cargo storage tank so that the liquid cargo stored in the liquid cargo storage tank can be supplied to the drum through the liquid cargo transfer line; a discharge line which is connected to a lower portion of the drum so as to load and unload the liquid cargo stored in the drum and in which a main pump for providing transfer pressure to the liquid cargo is installed; and a drum pressure control unit controlling pressure of the drum so as to maintain the flow rate of the liquid cargo discharged through the discharge line.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method and apparatus for transferring liquid cargo,

The present invention relates to a pressurized liquid cargo transferring apparatus and method.

In a conventional LNG carrier carrying a GTT membrane type cargo tank, a pump tower, which is a pipe structure, is formed in the cargo hold to ship or discharge the LNG. The pump tower supports various pipelines and LNG cargo pumps and also serves as a pipe for discharging LNG through a pipe.

1 is a view showing a pump tower installed in a conventional cargo hold.

Referring to FIG. 1, the LNG is transported through the same transport line outside the cargo hold when shipping and discharging the conventional LNG. In the cargo hold, the LNG is transported through a filling pipe (2) The LNG is loaded and unloaded through a discharge pipe (4). This is because the LNG cargo pump 5 is attached to the lowermost end of the discharge pipe 4 as a submerged type so that when the discharge pipe 4 is used for filling the cargo pump 5, Is reversed and damaged, and when the cooled LNG flows through the discharge pipe for supporting the structure, heat is shrunk to generate stress throughout the structure.

Especially, in case of failure of LNG Cargo Pump (5), it is impossible to repair it immediately. Therefore, each cargo window (1) should have 2 units, and additional line is required to install the emergency pump. Economic costs are incurred.

In addition, in order to solve the above-mentioned problem, it is impossible to construct a separate branch line, because it is difficult to develop an actuator capable of operating in a cryogenic environment. Therefore, in the conventional LNG inflow and outflow system in the tank of the ship, a filling pipe 2 is formed separately from the discharge pipe 4 to ship the LNG.

However, since a separate filling pipe 2 is required in the case of a conventional fluid inlet and outlet structure in a tank of a ship, the structure is complicated and a member required for supporting the filling pipe 2 in addition to the filling pipe 2 This requires a lot of economic cost to construct the equipment. Therefore, it is required to develop a fluid inflow and outflow structure in a tank that minimizes the use of related piping products and thereby increases the economic efficiency.

It is required to develop a technique for enabling the filling of the fluid through the discharge pipe 4 so that the inflow and outflow structure of the fluid in the tank satisfies this requirement.

An object of the present invention is to provide a pressurized liquid cargo transferring apparatus and method which can simplify the inflow and outflow structure of a liquid cargo in a cargo hold by unifying a filling pipe and a discharge pipe.

The problems to be solved by the present invention are not limited thereto, and other matters not mentioned can be clearly understood by those skilled in the art from the following description.

According to an aspect of the present invention, there is provided a liquid storage tank, comprising: a liquid cargo transfer line connected to a liquid cargo storage tank; A drum connected to the liquid cargo transfer line and providing a space for storing the liquid cargo; A pressurizing unit which pressurizes the liquid cargo storage tank so that the liquid cargo stored in the liquid cargo storage tank is supplied to the drum through the liquid cargo transfer line; A discharge line connected to a lower portion of the drum for unloading the liquid cargo stored in the drum and provided with a main pump for providing a transfer pressure to the liquid cargo; And a drum pressure regulator for regulating the pressure of the drum to maintain a constant flow rate of the liquid cargo discharged through the discharge line.

The drum pressure regulating unit may include a water level sensing member for measuring the level of the liquid cargo in the drum; A pressure measuring member for measuring the evaporation gas pressure in the drum; And a controller for receiving measured values from the water level sensing member and the pressure measuring member and controlling the amount of evaporated gas discharged in the drum.

The control unit may include a vapor control valve installed on the gas transfer line through which the evaporation gas in the drum is exhausted; And a control valve installed in the main pump and the discharge line.

The control unit may control the vapor control valve to decrease the amount of evaporated gas discharged through the gas transfer line when the level of the liquid cargo in the drum is higher than a predetermined level and the evaporation gas pressure in the drum is low, The vapor control valve may be controlled so that the liquid level of the liquid in the drum is raised to a predetermined level and the evaporated gas pressure in the drum is increased to increase the amount of evaporated gas discharged through the gas transfer line.

The apparatus may further include a peeling line connected to the liquid cargo transfer line and supplied with liquid from the outside.

Further, the pressurizing portion may further include a compressor for receiving and compressing the evaporated gas from the drum, and the evaporated gas compressed in the compressor may be provided to the liquid cargo storage tank through the gas transfer line.

Further, the pressurizing portion may further include a terminal gas line connected to the compressor and providing evaporative gas from the liquid cargo storing terminal.

Further comprising a cooling unit for preventing a temperature rise of the liquid cargo storage tank when the compressed evaporated gas is supplied to the liquid cargo storage tank, The cooling unit includes a spray nozzle installed inside the liquid storage tank for spraying the liquid cargo; And a cooling supply line connected to the injection nozzle and the drum, the cooling supply line being provided for supplying a part of liquid material stored in the drum to the injection nozzle by an auxiliary pump.

The pressurizing unit may further include a detour line connected to the gas transfer line to bypass the compressor to pressurize the volatile gas generated in the liquid storage tank, Can be compressed in the compressor through the bypass line and then supplied to the gas consumer.

The apparatus may further include a recovery line provided to store, in the drum, a surplus evaporated gas remaining in the evaporated gas compressed by the compressor.

According to another aspect of the present invention, there is provided a method of controlling a liquid storage tank, comprising: pressurizing a liquid storage tank using an evaporation gas so that liquid stored in the storage tank is transferred to the drum;

And discharging the liquid cargo stored in the drum to the liquid cargo storage terminal through pumping of the main pump, wherein the evaporation gas used to pressurize the liquid cargo storage tank is supplied to the compressor through the evaporator, And the discharging step may be provided with a liquid cargo transferring method of controlling the pressure of the drum to maintain a constant flow rate of the liquid cargo discharged from the drum.

In addition, the pressure control of the drum reduces the amount of evaporated gas discharged from the drum when the liquid level of the liquid in the drum is raised to a predetermined level and the evaporated gas pressure in the drum is low, The amount of evaporated gas exhausted from the drum can be increased if the evaporated gas pressure in the drum is high.

In addition, when the evaporation gas used to pressurize the liquid storage tank is insufficient in the pressurization step, the evaporation gas generated in the gas storage terminal is supplied to use, and the compressed evaporation gas is pressurized into the liquid storage tank It is possible to prevent the temperature of the liquid storage tank from being raised by spraying the liquid cargo.

The liquid cargo sprayed into the liquid cargo storage tank may be supplied from the drum.

Also, a portion of the liquid cargo is stored in the drum when the liquid cargo is loaded into the liquid cargo storage tank, and the pump cooldown before the main pump is used is performed using the liquid cargo stored in the drum And the evaporation gas generated in the pump cool down process may be supplied to the liquid storage tank.

According to the embodiment of the present invention, the flow rate discharged through the adjustment of the pressure of the drum can be always kept constant.

According to the embodiment of the present invention, since it is possible to fill and discharge the liquid cargo through the liquid cargo transfer line, it is not necessary to implement a separate pump tower inside the storage tank, which simplifies the structure and increases the price competitiveness .

According to the embodiment of the present invention, the liquid cargo stored in the drum can be used for various purposes.

The effects of the present invention are not limited to the above-mentioned effects, and the effects not mentioned can be clearly understood by those skilled in the art from the present specification and the accompanying drawings.

1 is a view showing a pump tower installed in a conventional cargo hold.
2 is a view showing a floating ocean structure to which a liquid cargo transfer device is applied.
3 is a view for explaining the process of loading (filling) the liquid cargo into the storage tank.
Fig. 4 is a view showing the movement path of the evaporative gas during the voyage.
5 is a view showing another movement path of the evaporation gas.
6 is a view for explaining the cooldown process of the main pump.
7 is a view for explaining a process of unloading liquid cargo from a storage tank.
FIG. 8 is a view showing a movement path of the evaporative gas during the gull navigation.
9 is a view showing a configuration for adjusting the pressure of the drum in the liquid cargo transfer apparatus.
10 is a table showing the pressure curve of the water level and the evaporation gas in the drum.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention is capable of various modifications and various embodiments, and specific embodiments are illustrated in the drawings and will be described in detail in the detailed description. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout the specification and claims. The description will be omitted.

2 is a view showing a floating ocean structure to which a liquid cargo transfer device is applied.

As can be seen in FIG. 2, the floating marine structure 10 has a hull 30 comprising a liquid cargo storage tanks 20. The liquid cargo loading / unloading in the liquid cargo storing tank 20 is performed by the liquid cargo transferring apparatus 100 installed in the hull 30.

In this case, the floating marine structure 10 is a marine floating structure (FPSO) and a natural gas production and storage facility for temporarily storing or treating the natural gas or crude oil when the drilling is performed at sea. FLNG (Floating Liquefied Natural Gas), or floating storage and regasification unit (FSRU). However, the present invention is not limited thereto, and it may be a structure having a storage tank for storing liquid cargo.

The liquid cargo transfer apparatus 100 of the present invention can perform the loading and unloading of liquid cargo by unifying the filling pipe and the discharge pipe, (Hereinafter referred to as "storage tank") 20 by using the evaporation gas stored in the drum 120 without the configuration of the underwater transfer pump.

The liquid cargo transfer device 10 of the present invention may be suitable for applications where the head pressure is low such as a small LNG tank or a storage tank of a liquid material having a remarkably low density (for example, liquefied hydrogen).

The liquid cargo transfer apparatus 100 includes a liquid cargo transfer line 110, a drum 120, a peeling line 130, a pressurization unit 200, a cooling unit 300, a discharge line 140, . ≪ / RTI >

The liquid cargo transfer line 110 is connected to the drum 120 installed on the deck of the hull 30 from the lower part to the upper part of the storage tank 20. Filling line 130 is connected to the liquid cargo transfer line 110.

The drum 120 has a storage space in which the liquid cargo is stored, and has a smaller capacity than the storage tank 20. [

The pressurizing portion 200 is provided to pressurize the liquid storage tank 20 so that the liquid cargo stored in the liquid cargo storage tank is supplied to the drum 120 through the liquid cargo transfer line 110. [

For example, the pressurization unit 200 may include a compressor 220, a gas transfer line 210, a terminal gas line 230, a pump gas line 240 and a bypass line 250. The compressor (220) is installed on the gas transfer line (210). The compressor 220 receives and compresses the evaporated gas from the drum 120 and the evaporated gas compressed by the compressor 220 is supplied to each of the storage tanks 20 through the gas transfer line 210. [ .

The gas transfer line 210 is connected to the upper end of the storage tank 20. The gas transfer line 210 can be used as a path for supplying the compressed evaporation gas to the storage tank 20, a path for discharging the evaporation gas of the storage tank. The gas transfer line 210 may be connected to a demand source supply line 212 for supplying evaporation gas to a customer. The first drum gas line 214 may be connected to the demand source supply line 212. The first drum gas line 214 is branched from the gas transfer line 210 corresponding to the interval between the compressor 220 and the drum 120 and connected to the demand source supply line 212. The first drum gas line 214 may be connected to a first point P1 on the gas transfer line 210 corresponding to the interval between the compressor and the storage tank.

The second drum gas line 216 is branched to the first drum gas line 214 and the second drum gas line 216 is branched at the second point P2 where the bypass line 250 and the gas transfer line 210 join .

The bypass line 250 may be connected to the gas transfer line 210 to bypass the compressor 220 to pressurize the vapor generated in the storage tank 20. One end of the bypass line is connected to the first point P2 on the gas transfer line in the interval between the compressor and the storage tank and the other end is connected to the second transfer port of the gas transfer line 210 in the interval between the compressor 220 and the drum 120 And may be connected to the third point P3. Meanwhile, the surplus evaporated gas remaining in the evaporated gas compressed by the compressor 220 may be transferred from the compressor 220 to the drum 120 through the first drum gas line 214. As such, the first drum gas line 214 can be used as a recovery line for recovering vaporized gas as needed.

The exhaust line 260 is connected to the bypass line 250. The exhaust line 260 may be connected to another consumer (additional consumer) that requires evaporative gas.

The compressor 200 is connected to a terminal gas line 230 which is supplied with evaporative gas from a liquid cargo storage terminal (not shown). The pressurization portion 200 can be supplied with the evaporation gas from the liquid cargo storage terminal through the terminal gas line 230 when the compressed evaporation gas to be supplied to the storage tank 20 is insufficient. The pump 220 may be connected to a pump gas line 240 that is supplied with evaporative gas from the main pump 150.

The discharge line 140 is connected to the lower portion of the drum 120. On the discharge line 140, a main pump 150 is installed. The main pump 150 is provided to impart the transfer pressure to the liquid cargo stored in the drum 120.

The cooling unit 300 is provided to prevent a temperature rise of the storage tank 20 when compressed evaporation gas is supplied to the storage tank 20. For example, the cooling unit 300 may include an injection nozzle 310, a cooling supply line 320, and an auxiliary pump 330.

The spray nozzle 310 is installed in the upper part of the storage tank 20 to spray the liquid cargo.

The cooling supply line 320 connects the spray nozzle 310 and the drum 120. The auxiliary pump 330 applies a transfer pressure for supplying a part of the liquid cargo stored in the drum 120 to the injection nozzle 310.

3 is a view for explaining the process of loading (filling) the liquid cargo into the storage tank. For convenience of explanation, the conveyance path of the liquid cargo is indicated by a dotted line and the conveyance path of the evaporated gas is indicated by a thick solid line. In FIGS. 3 to 8, among the valves installed in the respective lines, the valves indicated by black in the inside are closed, and the valves in the other lines are open.

As shown in FIG. 3, the liquid cargo is stored in the storage tank 20 via the filling line 130, the liquid cargo transfer line 110, and the like. At this time, a part of the liquid cargo is stored in the storage space of the drum 120. The liquid cargo stored in the storage space of the drum 120 may be used for cooldown of the main pump 150. The evaporation gas generated in the storage space of the drum 120 and the evaporation gas generated in the storage tank 20 can be supplied to the additional consumers through the exhaust line 260 connected to the bypass line 250.

Here, an additional customer needs evaporative gas and can be driven by using it as raw material. As an example, the additional customer may be, but is not limited to, a generator (e.g., DFDG), a gas fired unit (GCU), a boiler (e.g.

Fig. 4 is a view showing the movement path of the evaporative gas during the voyage.

For convenience of explanation, the conveyance path of the liquid cargo is indicated by a dotted line and the conveyance path of the evaporated gas is indicated by a thick solid line.

4, the evaporation gas generated in the storage tank 20 at the time of laden voyage filled with liquid cargo in the storage tank passes through the gas transfer line 210 and the bypass line 250 to the compressor 220 And then supplied to the customer through the demand-supply line 212. And the evaporated gas in the drum 120 may be supplied when the amount of evaporative gas generated in the storage tank 20 is insufficient. Alternatively, the liquid supply can be supplied to the customer by utilizing the auxiliary pump 330 installed in the cooling supply line 320.

For reference, a customer can use a vaporized gas (or liquefied gas) which is pressurized to about 200 to 400 bar by a compressor and vaporized, can be a high-pressure engine using a high-pressure evaporation gas of about 300 bar, An engine for rotating the propeller shaft directly or an engine for generating other power.

5 is a view showing another movement path of the evaporation gas.

For convenience of explanation, the conveying path of the evaporation gas is indicated by a thick solid line.

Referring to FIG. 5, when the amount of evaporative gas used at the demand side is decreased due to slow running, the excess evaporative gas is compressed through the compressor 220 and then flows through the first drum gas line 214 at the first point P1 May be stored in the drum 120.

6 is a view for explaining the cooldown process of the main pump.

For convenience of explanation, the conveying path of the evaporation gas is indicated by a thick solid line.

Referring to FIG. 6, since the main pump 150 is exposed to the outside atmosphere unlike the submerged pump installed in the storage tank, the main pump 150 must perform a cool-down operation before performing the lowering operation. The cool down of the main pump 150 is performed using the liquid cargo stored in the drum 120.

In this process, the evaporated gas generated in the main pump 150 is supplied to the compressor 220 through the pump gas line 240. In addition, evaporative gas in the drum 120 and in the storage tank on the right can also be provided to the compressor 220. [ The evaporated gas compressed in the compressor 220 (hereinafter referred to as compressed evaporation gas) is supplied to the storage tank on the left side of the two storage tanks through the gas transfer line 210. In the storage tank on the left side, the liquid cargo is transferred to the drum 120 through the liquid cargo transfer line 110 by the pressing force of the compressed evaporative gas. Accordingly, the drum 120 receives the liquid cargo used for cooldown of the main pump 150.

7 is a view for explaining a process of unloading liquid cargo from a storage tank. For convenience of explanation, the conveyance path of the liquid cargo is indicated by a dotted line and the conveyance path of the evaporated gas is indicated by a thick solid line.

7, the loading operation presses the two storage tanks 20 by the pressurizing unit 200, and the liquid cargo stored in the storage tank 20 by the pressurizing force of the compressed evaporative gas is discharged to the liquid cargo transfer line 110, To the drum (120).

In this pressurizing process, the compressed evaporation gas passing through the compressor 220 may cause the temperature inside the storage tank 20 to rise because the temperature is higher than the liquidus temperature in the storage tank 20 at a normal temperature. In order to minimize such a problem, in the pressurizing process, the internal temperature of the storage tank 20 is prevented from rising through the cooling unit 300. That is, when the compressed evaporation gas is pressurized into the storage tank 20 and the liquid cargo is sprayed inside the storage tank 20, the cooled liquid refrigerant cools the compressed evaporation gas, and the temperature rise of the storage tank 20 And the required amount of the compressed evaporative gas discharged through the compressor 220 can be reduced, thereby reducing the capacity of the compressor 220. Liquid cargoes that are sprayed into the storage tank 20 are supplied from the drum 120.

Meanwhile, the liquid cargo transferred from the storage tank 20 to the drum 120 is transferred to the liquid cargo storage terminal (for example, a carrier or a ground storage tank) (not shown) through the discharge line 140, The transfer of the liquid cargo is performed by the main pump 150.

FIG. 8 is a view showing a movement path of the evaporative gas during the gull navigation.

For convenience of explanation, the conveying path of the evaporation gas is indicated by a thick solid line.

Referring to FIG. 8, since the amount of evaporative gas generated from the storage tank 20 is reduced during the collinear voyage, the evaporative gas necessary for the operation can be supplied from the liquid cargo stored in the drum 120. That is, the liquid cargo in the drum 120 may be supplied to an evaporator (not shown) through a cooling supply line 320 and then supplied to a customer.

9 is a view showing a configuration for adjusting the pressure of the drum in the liquid cargo transfer apparatus.

9, the liquid cargo transfer apparatus 100 has a drum pressure regulating unit 1220. The drum pressure regulating unit 122 regulates the pressure of the liquid to be discharged through the discharge line 142 Thereby adjusting the pressure of the drum 120.

The drum pressure regulating portion 122 includes a water level detecting member 124 for measuring the level of liquid cargo in the drum 120, a pressure measuring member 126 for measuring the evaporated gas pressure in the drum 120, And a control unit 128 for controlling the amount of evaporated gas discharged from the drum 120 by receiving measured values from the pressure measuring member 124 and the pressure measuring member 126.

The control unit 128 controls the vapor control valve 211, the main pump 150 and the control valve 142 installed on the discharge line 140, which are installed on the gas transfer line 210 on which the evaporation gas in the drum 120 is exhausted Respectively.

The control unit 128 controls the amount of the evaporated gas discharged through the gas transfer line 210 to be reduced so that the liquid level of the liquid cargo in the drum 120 is raised to a predetermined level and the evaporated gas pressure in the drum 120 is low, (211). The control unit 128 controls the amount of evaporated gas discharged through the gas transfer line 210 to be increased so that the level of the liquid cargo in the drum 120 is raised to a predetermined level and the pressure of the evaporated gas in the drum 120 is high. Thereby controlling the valve 211.

If the flow rate of the water flowing into the drum 120 is greater than the flow rate of the water flowing into the discharge line 140, the water level of the drum 120 is increased and the pressure of the drum 120 is increased accordingly. As a result, the pressure difference between the storage tank 20 and the drum 120 is reduced, and the flow rate of the water flowing into the drum 120 is reduced naturally. On the other hand, when the water level of the drum 120 is lowered, the pressure in the drum 120 is reduced, and the flow rate of the water flowing into the drum 120 is increased. However, the liquid refrigerant in the drum 120 is vaporized by the incoming heat and is thus pressurized in the drum 120. This portion of the liquid 120 is pressurized in the drum by the water level and the pressure curve P of the evaporated gas as the reference Can be controlled.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

110: liquid cargo transfer line 120: drum
130: Peeling line 140: Emissive line
150: main pump 200:
300: Cooling section

Claims (9)

A liquid cargo transfer line connected to a liquid cargo storage tank;
A drum connected to the liquid cargo transfer line and providing a space for storing the liquid cargo;
A pressurizing unit which pressurizes the liquid cargo storage tank so that the liquid cargo stored in the liquid cargo storage tank is supplied to the drum through the liquid cargo transfer line; And
And a discharge line connected to a lower portion of the drum for unloading the liquid cargo stored in the drum and provided with a main pump for providing a transfer pressure to the liquid cargo;
The pressing portion
And a compressor for receiving and compressing the evaporated gas from the drum,
Wherein the evaporated gas compressed in the compressor is provided to the liquid cargo storage tank through the gas transfer line. The method according to claim 1,
Further comprising a drum pressure regulator for regulating the pressure of the drum to maintain a constant flow rate of the liquid cargo discharged through the discharge line;
The drum pressure regulator
A water level sensing member for measuring the level of the liquid cargo in the drum;
A pressure measuring member for measuring the evaporation gas pressure in the drum; And
And a controller for receiving measured values from the water level sensing member and the pressure measuring member and controlling an evaporation gas discharge amount in the drum. 3. The method of claim 2,
The control unit
A vapor control valve installed on a gas transfer line through which evaporation gas in the drum is exhausted; And
And controls the main pump and the control valve installed in the discharge line. The method of claim 3,
The control unit
Controlling the vapor control valve so that the amount of evaporated gas exhausted through the gas transfer line is reduced when the evaporated gas pressure in the drum with respect to the liquid level of the liquid in the drum is lower than a preset ratio,
And controls the vapor control valve so that the amount of evaporated gas exhausted through the gas transfer line is increased if the evaporated gas pressure in the drum relative to the level of the liquid cargo in the drum is higher than a predetermined ratio. 3. The method according to claim 1 or 2,
Further comprising a peeling line connected to the liquid cargo transfer line and adapted to receive liquid cargo from the outside. The method according to claim 1,
The pressing portion
And a terminal gas line connected to the compressor and providing an evaporative gas from the liquid cargo storage terminal. The method according to claim 1,
Further comprising: a cooling unit for preventing a temperature rise of the liquid cargo storage tank when the compressed evaporated gas is supplied to the liquid cargo storage tank;
The cooling unit
A spray nozzle installed inside the liquid storage tank for spraying the liquid cargo; And
And a cooling supply line connected to the injection nozzle and the drum, the cooling supply line being provided for supplying a part of the liquid cargo stored in the drum to the injection nozzle by an auxiliary pump. The method according to claim 1,
The pressing portion
Further comprising a bypass line bypassing the compressor to the gas transfer line for pressurizing the vapor generated in the liquid storage tank,
Wherein the evaporated gas generated in the liquid storage tank is compressed by the compressor through the bypass line and then supplied to the gas consumer. 9. The method of claim 8,
Further comprising a recovery line provided for storing, in the drum, a surplus evaporated gas remaining in the evaporated gas compressed by the compressor, the recovered evaporated gas being supplied to the gas consumer.

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