KR20220140910A - Liquefied gas loading and gas treatment system for trial operation of propulsion ship, and method thereof - Google Patents

Abstract

Disclosed are a liquefied gas loading and gas treatment system for the trial operation of a propulsion ship, and a method thereof. According to an embodiment of the present invention, a liquefied gas loading and gas treatment system for the trial operation of a propulsion ship comprises: a first loading line for loading liquefied gas, supplied from the supply tank of a bunkering ship, to the first storage tank of a propulsion ship onshore; a second loading line branching off from the first loading line, and connected to a second storage tank; a discharge line communicating with the second loading line; a compressor for receiving and compressing boil-off gas generated by the liquefied gas supplied to the first storage tank through the first loading line; a heater for heating the compressed boil-off gas; and a compression heating line for connecting the first storage tank, the compressor, the heater, and the second storage tank and supplying the heated boil-off gas to the second storage tank. The heated boil-off gas can be filled in the second storage tank through the compression heating line, and nitrogen gas present in the second storage tank can be discharged to the outside through the second loading line and the discharge line. Therefore, the liquefied gas loading and gas treatment system can efficiently perform boil-off gas circulation supply, pressure control, temperature control, and gassing-up work.

Description

LIQUEFIED GAS LOADING AND GAS TREATMENT SYSTEM FOR TRIAL OPERATION OF PROPULSION SHIP, AND METHOD THEREOF

The present invention relates to a liquefied gas loading and gas treatment system and a method thereof for commissioning a propulsion ship.

Propulsion ships that use liquefied gas such as LNG (Liquefied Natural Gas) as fuel are tested offshore after they are built to check whether storage tanks, pumps, and various facilities operate normally.

Prior to performing a test run by moving the propulsion ship offshore, liquefied gas loading and gas processing are performed. Specifically, liquefied gas to be used as fuel is loaded into one of the storage tanks of the propulsion ship according to a set amount, and the boil-off gas generated inside the storage tank supplied with the liquefied gas is heated by a heater and then circulated and supplied to another storage tank. . Since the other storage tanks are in a state in which inertting with nitrogen gas has been performed in advance, the nitrogen gas in the other storage tanks is discharged to the outside by the above-described boil-off gas supply.

However, in the conventional process, the boil-off gas supplied to another storage tank after being heated by a heater was difficult to circulate and supply smoothly due to the low pressure, which made it difficult to control the pressure inside the other storage tanks.

In addition, the flow of the gas is not smooth due to the low pressure, and thus, smooth temperature control of the boil-off gas is not performed well by the heater, so it is difficult to replace the gas while maintaining the gas layer in the other storage tank in a stable state.

An embodiment of the present invention compresses and heats boil-off gas generated from liquefied gas loaded in the first storage tank of the propulsion ship and supplies it into the second storage tank, so that the boil-off gas circulation supply, pressure control, temperature control and gassing-up work are performed. An object of the present invention is to provide a liquefied gas loading and gas processing system and a method thereof for test operation of a propulsion ship that can be efficiently performed.

According to an aspect of the present invention, a first loading line for loading the liquefied gas supplied from the supply tank of the bunkering ship on the shore to the first storage tank of the propulsion ship; a second loading line branched from the first loading line and connected to a second storage tank; a discharge line communicating with the second loading line; a compressor for receiving and compressing boil-off gas generated by the liquefied gas supplied to the first storage tank through the first loading line; a heater for heating the compressed boil-off gas; and a compression heating line connecting the first storage tank, the compressor, the heater, and the second storage tank, and supplying the heated boil-off gas to the second storage tank. A liquefied gas loading and gas treatment system for test operation of a propulsion ship that fills the inside of the second storage tank through a line and discharges nitrogen gas present in the second storage tank to the outside through the second loading line and the discharge line, and its We want to provide a way

Separation that is provided at a connection portion of the second loading line connected to the first loading line, and separates the first loading line and the second loading line to prevent movement of the fluid between the first loading line and the second loading line It may further include a member.

The separation member may include at least one of a spectacle flange and an isolation valve.

Further comprising: a cooling unit for receiving and cooling the liquefied gas stored in the first storage tank; and a recovery line for reducing the amount of BOG generated inside the first storage tank by returning the cooled liquefied gas to the first storage tank can do.

It may further include a cool-down line for supplying the liquefied gas stored in the first storage tank to the second storage tank, and an injection nozzle for injecting the liquefied gas supplied through the cool-down line into the second storage tank. have.

According to another aspect of the present invention, (a) supplying liquefied gas from the supply tank of the bunkering vessel on the shore to the first storage tank of the propulsion vessel; (b) receiving and compressing the boil-off gas generated inside the first storage tank; (c) heating the compressed boil-off gas and supplying it to a second storage tank; And (d) discharging the nitrogen gas present in the second storage tank to the outside; to provide a liquefied gas loading and gas treatment system and a method for the test operation of a propulsion ship comprising a.

The method may further include cooling the supplied liquefied gas stored in the first storage tank, and injecting the cooled liquefied gas into the first storage tank.

Liquefied gas loading and gas processing system and method for test operation of a propulsion ship according to an embodiment of the present invention compresses and heats boil-off gas generated from liquefied gas loaded in a first storage tank of a propulsion ship and supplies it to the inside of the second storage tank By doing so, BOG circulation supply, pressure control, temperature control, and gassing-up work can be performed efficiently.

The effects of the present invention are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

1 shows a liquefied gas loading and gas processing system for a test run of a propulsion ship according to an embodiment of the present invention.
FIG. 2 shows a liquefied gas loading and gas processing method using the liquefied gas loading and gas processing system of FIG. 1 .

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments introduced below are provided as examples so that the spirit of the present invention can be sufficiently conveyed to those of ordinary skill in the art to which the present invention pertains. The present invention is not limited to the embodiments described below and may be embodied in other forms. In order to clearly explain the present invention, parts irrelevant to the description are omitted from the drawings, and in the drawings, the width, length, thickness, etc. of components may be exaggerated for convenience. Like reference numerals refer to like elements throughout.

Referring to FIG. 1 , the liquefied gas loading and gas treatment system 100 for test operation of a propulsion ship according to an embodiment of the present invention propels the liquefied gas supplied from a supply tank (not shown) of a bunkering ship in Onshore. A first loading line (L1) for loading into the first storage tank 101 of the line, a second loading line (L2) branched from the first loading line (L1) and connected to the second storage tank 102, and a second Compressor 110 for receiving and compressing boil-off gas generated by the liquefied gas supplied to the first storage tank 101 through the discharge line L3 communicating with the second loading line L2 and the first loading line L1 ) and the heater 120 for heating the boil-off gas compressed by the compressor 110, the first storage tank 101, the compressor 110, the heater 120 and the second storage tank 102 are connected. , and a compression heating line (L4) for supplying the boil-off gas heated by the heater (120) to the second storage tank (102).

In addition, the liquefied gas supply and gas processing system 100 is provided at the connection portion of the second loading line L2 connected to the first loading line L1, and the first loading line L1 and the second loading line ( It may include a separation member 130 for separating the L2) to prevent the movement of the fluid between the first loading line (L1) and the second loading line (L2).

In addition, the liquefied gas supply and gas processing system 100 receives the liquefied gas stored in the first storage tank 101 and cools the cooling unit 140 , and the first liquefied gas cooled by the cooling unit 140 . It may include a recovery line (L5) for reducing the amount of BOG generated inside the first storage tank (101) by returning it to the storage tank (101).

In addition, the liquefied gas supply and gas processing system 100 includes a cool-down line L6 and a cool-down line L6 for supplying the liquefied gas stored in the first storage tank 101 to the second storage tank 102 . It may include an injection nozzle 105 for injecting the liquefied gas supplied through the second storage tank 102 into the interior.

Hereinafter, each component of the liquefied gas supply and gas processing system 100 will be described in detail. In the embodiment of the present invention, the first storage tank 101 on the stern side and the second storage tank 102 on the bow side will be described as an example, but storage tanks may be further provided on the stern side and the bow side, respectively.

The first storage tank 101 and the second storage tank 102 may be, for example, a membrane type or a pressurized tank, and may store liquefied natural gas (LNG) as a cryogenic fluid. In this case, the first storage tank 101 may be in a state in which an inerting operation and a cool down operation are completed in advance, and the nitrogen gas inside is discharged. In addition, the second storage tank 102 may be in a state in which the inerting operation is completed in advance and the nitrogen gas is filled therein. The nitrogen gas used for the inerting operation may be generated from a nitrogen gas generator (Nitrogen Generating Equipment) provided in the propulsion ship. The cool-down operation may be performed by a method of injecting the liquefied gas supplied from the supply tank (not shown) of the bunkering ship into the first storage tank 101 .

The first loading line L1 loads the liquefied gas supplied from the supply tank (not shown) of the bunkering ship into the first storage tank 101 of the propulsion ship. The first loading line L1 is disposed close to the inner bottom surface of the first storage tank 101 of the propulsion ship, so that liquefied gas may be loaded in a bottom filling manner. In another example, the liquefied gas may be loaded into the first storage tank 101 by a Top Filling method through a Top Filling Line (not shown) branched from the first loading line L1 .

The first loading line L1 may include a liquid line, and thus a loading rate may be increased. On the other hand, in the prior art, the loading operation was performed using a spray line, and the loading rate was low, so it took a long time to load the liquefied gas. Since the liquid line has a larger diameter than the spray line, liquefied gas loading can be performed effectively.

In addition, each of the storage tanks (101, 102) is provided with a manifold (Manifold) to load and discharge the cargo. The first loading line L1 may be configured as a cryogenic stainless steel pipeline to be connected to a manifold receiving liquefied gas from a bunker line.

The second loading line (L2) is branched from the first loading line (L1), is connected to the second storage tank (102), and is to be loaded with liquefied gas into the second storage tank (102) after performing a trial run on the offshore. can

In addition, the second loading line L2 serves to discharge nitrogen gas inside the second storage tank 102 together with the discharge line L3 by the boil-off gas supplied from the first storage tank 101 to the outside. can do.

That is, the discharge line L3 communicates with the second loading line L2, and discharges the nitrogen gas inside the second storage tank 102 transferred through the second loading line L2 to the outside. At this time, by separating the first loading line (L1) and the second loading line (L2) by the separation member 130 to prevent the movement of the fluid between the first loading line (L1) and the second loading line (L2) The nitrogen gas inside the second storage tank 102 transferred through the loading line L2 may be discharged to the outside through the discharge line L3.

The compressor 110 receives the liquefied gas boil-off gas in the first storage tank 101 through the compression heating line L4 and compresses it. Here, the compressor 110 may include, for example, a low pressure compressor for compressing the boil-off gas to about 0.5 bar, and smooth circulation to the second storage tank 102 may be achieved by the boil-off gas compression.

The heater 120 heats the boil-off gas compressed by the compressor 110 and supplies it to the second storage tank 102 . The boil-off gas compressed by the compressor 110 is heated and supplied to the inside of the second storage tank 102 , thereby replacing the inert gas (nitrogen gas) in the second storage tank 102 with natural gas. Up) work can be done. At this time, since BOG circulates in a state compressed by the compressor 110 , temperature control by the heater 120 is easy, and pressure control and BOG circulation in the second storage tank 102 are smoothly performed. can

The boil-off gas heated by the heater 120 is supplied into the second storage tank 102 through the compression heating line L4, and the nitrogen gas present in the second storage tank 102 is transferred to the second loading line L2. ) and may be discharged to the outside through the discharge line (L3).

The separation member 130 is provided at a connection portion of the second loading line L2 connected to the first loading line L1, and separates the first loading line L1 and the second loading line L2 to obtain a first The movement of the fluid between the loading line (L1) and the second loading line (L2) is prevented.

That is, when the boil-off gas heated by the heater 120 flows into the second storage tank 102 through the compression heating line L4, the nitrogen gas present in the second storage tank 102 is loaded with the second loading. It can be effectively discharged to the outside through the line (L2) and the discharge line (L3) connected thereto.

The separation member 130 may include, for example, one or more of a spectacle flange and an isolation valve.

The cooling unit 140 receives at least a portion of the liquefied gas stored in the first storage tank 101 through the cooling line L5-1 and cools it, and the liquefied gas cooled by the cooling unit 140 is cooled by a recovery line ( It is recovered to the first storage tank 101 through L5) to reduce the amount of BOG generated inside the first storage tank 101 . At this time, the injection nozzle 104 may be provided at the end of the recovery line L5 to inject the liquefied gas cooled by the cooling unit 140 into the first storage tank 101 . Through this, the amount of boil-off gas generated inside the first storage tank 101 can be reduced.

The cooling unit 140 may cool the liquefied gas by, for example, performing heat exchange between the refrigerant and the liquefied gas supplied from the first storage tank 101 . Specifically, the cooling unit 140 compresses a medium-temperature and low-pressure refrigerant to convert it into a high-temperature and high-pressure refrigerant, converts the compressed refrigerant into a medium-temperature and high-pressure state by exchanging heat with cooling water, lowers the temperature of the refrigerant, and expands the refrigerant to low temperature It may include means for converting to a low pressure and performing heat exchange between the expanded refrigerant and the liquefied gas supplied from the first storage tank 101 .

The cool-down line L6 may be provided to be branched from the cooling line L5 - 1 and be connected to the second storage tank 102 . The cool-down line L6 supplies the liquefied gas pumped by the pump inside the first storage tank 101 to the second storage tank 102 . The injection nozzle 105 provided at the end of the cool-down line L6 injects the liquefied gas supplied through the cool-down line L6 into the second storage tank 102 . Through this, a cool-down operation for the second storage tank 102 may be performed. This work can be done offshore during the commissioning process.

Hereinafter, a liquefied gas supply and gas processing method using the liquefied gas supply and gas processing system 100 described above based on FIGS. 1 and 2 will be described.

A propulsion ship using a liquefied gas such as LNG as a fuel is dried and then moved to the offshore to inspect whether the storage tank, pump, and various facilities operate normally while performing a test operation. A certain amount of liquefied gas to be used as fuel is loaded.

In this case, prior to loading the liquefied gas into the first storage tank 101 , an inerting operation and a cool-down operation may be performed on the first storage tank 101 in advance. In addition, the second storage tank 101 may be in a state in which the inerting operation is performed in advance and the nitrogen gas is filled therein.

First, liquefied gas is supplied from the supply tank of the bunkering ship to the first storage tank 101 of the propulsion ship on the shore (S1). Here, the liquefied gas stored in the first storage tank 101 is supplied and cooled by the cooling unit 140, and the cooled liquefied gas is supplied to the first storage tank through the injection nozzle 104 provided at the end of the recovery line L5. (101) The process of spraying the inside may be performed.

The term "onshore" used in an embodiment of the present invention means land, and includes a yard that means a shipyard. In other words, onshore is used in a broader sense than yard. That the operation of supplying liquefied gas from the supply tank of the bunkering vessel on the shore to the first storage tank 101 of the propulsion vessel is performed includes that the operation is performed at the berthing place (quay wall).

Next, the boil-off gas generated inside the first storage tank 101 is supplied and compressed by the compressor 110 (S2).

Next, the boil-off gas compressed by the compressor 110 is heated by the heater 120 and supplied to the second storage tank 102 (S3).

Next, while filling the boil-off gas heated by the heater 120 in the second storage tank 102, the nitrogen gas present in the second storage tank 102 is discharged to the outside (S4). At this time, by separating the first loading line (L1) and the second loading line (L2) by the separation member 130 to prevent the movement of the fluid between the first loading line (L1) and the second loading line (L2) The nitrogen gas inside the second storage tank 102 transferred through the loading line L2 may be discharged to the outside through the discharge line L3.

After that, the propulsion ship is moved offshore using the liquefied gas stored in the first storage tank 101 as a fuel, and then a trial operation process is performed.

For example, in the test operation process, the liquefied gas stored in the first storage tank 101 is transferred to the inside of the second storage tank 102 through the cool-down line L6 and sprayed to the injection nozzle 105 to cool down. ) may include performing the task.

In addition, the test operation process may include one or more of a health test for the secondary barrier, a cold pipe test, a pumping test, and a loading arm test.

In the above, specific embodiments have been shown and described. However, the present invention is not limited to the above-described embodiments, and those of ordinary skill in the art to which the invention pertains can make various changes without departing from the spirit of the invention described in the claims below. will be able

101: first storage tank 102: second storage tank
105: injection nozzle 110: compressor
120: heater 130: separation member
140: cooling unit L1: first loading line
L2: Second loading line L3: Discharge line
L4: Compression heating line L5: Recovery line
L6: Cool Down Line

Claims (7)

a first loading line for loading the liquefied gas supplied from the supply tank of the bunkering ship on the shore to the first storage tank of the propulsion ship;
a second loading line branched from the first loading line and connected to a second storage tank;
a discharge line communicating with the second loading line;
a compressor for receiving and compressing boil-off gas generated by the liquefied gas supplied to the first storage tank through the first loading line;
a heater for heating the compressed boil-off gas; and
A compression heating line connecting the first storage tank, the compressor, the heater, and the second storage tank, and supplying the heated boil-off gas to the second storage tank;
For test run of a propulsion ship that fills the heated boil-off gas into the second storage tank through the compression heating line and discharges the nitrogen gas present in the second storage tank to the outside through the second loading line and the discharge line Liquefied gas loading and gas handling systems. According to claim 1,
Separation that is provided at a connection portion of the second loading line connected to the first loading line, and separates the first loading line and the second loading line to prevent movement of the fluid between the first loading line and the second loading line Liquefied gas loading and gas processing system for test operation of the propulsion ship further comprising a member. 3. The method of claim 2,
The separation member is a liquefied gas loading and gas processing system for a propulsion ship commissioning including at least one of a spectacle flange and an isolation valve. According to claim 1,
a cooling unit for cooling by receiving the liquefied gas stored in the first storage tank;
Liquefied gas loading and gas treatment system for test operation of a propulsion ship further comprising a recovery line for reducing the amount of BOG generated inside the first storage tank by returning the cooled liquefied gas to the first storage tank. According to claim 1,
a cool-down line for supplying the liquefied gas stored in the first storage tank to the second storage tank;
A liquefied gas loading and gas processing system for test operation of a propulsion ship further comprising an injection nozzle for injecting the liquefied gas supplied through the cool-down line into the second storage tank. (a) supplying liquefied gas from the supply tank of the bunkering vessel on the shore to the first storage tank of the propulsion vessel;
(b) receiving and compressing the boil-off gas generated inside the first storage tank;
(c) heating the compressed boil-off gas and supplying it to a second storage tank; and
(d) discharging nitrogen gas present in the second storage tank to the outside; 7. The method of claim 6,
After step (a),
Cooling by receiving the liquefied gas stored in the first storage tank,
Liquefied gas loading and gas processing method for test operation of a propulsion ship further comprising the step of injecting the cooled liquefied gas into the first storage tank.

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