KR102138408B1 - Ship - Google Patents

Abstract

Ship according to an embodiment of the present invention, a cargo storage tank for storing cargo; A manifold that is connected to a loading line for loading the cargo and an unloading line for unloading cargo of the cargo storage tank to the outside, so that cargo passes between the external and the cargo storage tank; An evaporation gas discharge line connected to the outside from the cargo storage tank through the manifold and discharging evaporation gas generated in the cargo storage tank when loading the cargo; And a branch line branched from the boil-off gas discharge line and connected to the manifold, and boil-off gas discharged through the boil-off gas discharge line is external to the outside without being pressurized by a differential pressure between the cargo storage tank and the outside. As it is delivered to, the discharge amount is characterized in that it is controlled via the branch line.

Description

Ship{Ship}

The present invention relates to a ship.

Liquefied natural gas is liquefied by cooling the methane obtained by refining natural gas collected from a gas field. It is a colorless and transparent liquid with little pollutants and high heat, making it an excellent fuel. On the other hand, liquefied petroleum gas is a fuel made of liquid by compressing gas mainly composed of propane (C3H8) and butane (C4H10), which come out with oil in the oil field at room temperature. Liquefied petroleum gas, like liquefied natural gas, is colorless and odorless, and is widely used as fuel for household, business, industrial, and automobile applications.

The liquefied gas is stored in a liquefied gas storage tank installed on the ground or in a liquefied gas storage tank provided in a ship that is a transportation means for navigating the ocean. The liquefied natural gas is liquefied to a volume of 1/600. It is reduced, and liquefied petroleum gas has the advantage of high storage efficiency because it is reduced to 1/260 of propane and 1/230 of butane by liquefaction.

The liquefied gas is supplied and used to various demand sources. Recently, LPG fuel supplying method for driving the engine using LPG as fuel in LPG carriers carrying liquefied natural gas has been developed, and thus LPG is used as fuel for the engine. The method used is also applied to other ships other than LPG carriers.

In particular, natural gas is produced in the state of liquefied natural gas liquefied at the place of production, and then transported over a long distance to the destination by an LNG carrier, then an LNG floating storage and regasfication unit (FSRU) or It is regasified through the landing terminal and supplied to the consumer. To this end, a floating liquefied gas storage line equipped with an FSRU is formed by connecting a transfer line (hose) provided to directly connect to a consumer.

That is, the floating liquefied gas storage vessel can be transported, stored and stored by receiving liquefied gas (LNG, Liquefied Natural Gas) carried by the liquefied gas carrier (LNGC) and vaporized and supplied if necessary.

On the other hand, FSRU is used as an LNG carrier that is used as an LNG carrier that transports and supplies liquefied gas to other LNG carriers while providing liquefied gas as well as floating liquefied gas storage vessels in which FSRUs are provided. There is FSRU line.

The evaporation gas discharge line, which is connected to the manifold of the LNG-FSRU line and discharges the evaporation gas, is made larger than the size capable of measuring the evaporation gas emission. That is, when the vessel is used for transporting LNG, the amount of the evaporated gas discharged through the evaporated gas discharge line is constant, so that the size of the evaporated gas discharge line is large (for example, the diameter is 600 mm, and the evaporated gas discharge amount can be measured). Size), it needs to be adjusted according to the size of other LNG carriers to which the amount of evaporated gas is supplied when used as an FSRU.

However, the diameter of the evaporation gas discharge line is large in order to combine both FSRU and LNG transportation while achieving rapid evaporation gas discharge, and it is difficult to control the amount of evaporation gas discharged through the evaporation gas discharge line.

The present invention was created to improve the prior art, and an object of the present invention is to provide a vessel capable of discharging evaporated gas without driving a compressor or the like when loading LNG by the LNG-FSRU ship-to-ship. .

Ship according to an embodiment of the present invention, a cargo storage tank for storing cargo; A manifold that is connected to a loading line for loading the cargo and an unloading line for unloading cargo of the cargo storage tank to the outside, so that cargo passes between the external and the cargo storage tank; An evaporation gas discharge line connected to the outside from the cargo storage tank through the manifold and discharging evaporation gas generated in the cargo storage tank when loading the cargo; And a branch line branched from the boil-off gas discharge line and connected to the manifold, and boil-off gas discharged through the boil-off gas discharge line is external to the outside without being pressurized by a differential pressure between the cargo storage tank and the outside. As it is delivered to, the discharge amount is characterized in that it is controlled via the branch line.

Specifically, the evaporation gas discharge line, the main line connected from the cargo storage tank; A first line branched from the main line, joined to the manifold, and provided with a compressor for compressing the evaporation gas; And a second line branched from the main line so as to be spaced apart from the first line, joined to the manifold, and branched from the branch line.

Specifically, the diameter of the branch line may be 1/2 to 2/3 smaller than the diameter of the evaporation gas discharge line.

Specifically, a compressor for compressing the boil-off gas may be provided in the boil-off gas discharge line.

Specifically, after branching from the evaporation gas discharge line, the auxiliary line bypassing the compressor may be further provided by joining the evaporation gas discharge line.

Specifically, a control valve and a flow meter may be provided in the branch line.

Specifically, the control valve, it is possible to adjust the flow rate of the evaporation gas delivered to the outside through the manifold.

Specifically, a block valve for controlling whether or not the boil-off gas is discharged may be provided in the boil-off gas discharge line.

Specifically, the control valve may control the flow rate of the evaporated gas while maintaining the pressure of the cargo storage tank higher than the external pressure.

Specifically, the outside may be a cargo supply tank provided at a shipping location.

Specifically, the cargo storage tank may be made of a tank provided on the LNG-FSRU line.

Vessel according to the present invention, without operating the compressor (High Duty Compressor) using the pressure of the tank provided on the LNG-FSRU line while discharging the evaporation gas, the evaporation gas is branched from the evaporation gas discharge line discharged evaporation gas Since the size is smaller than the discharge line, it is possible to control the amount of evaporated gas emission through a branch line that can control the amount of emissions, thus saving energy due to the non-driving of the compressor, and the operation equipment is reduced when the evaporated gas is discharged. Can be done.

1 is a view showing a vessel according to an embodiment of the present invention.

The objects, specific advantages and novel features of the present invention will become more apparent from the following detailed description and preferred embodiments, which are associated with the accompanying drawings. In addition, it should be noted that, in addition to reference numerals to the components of each drawing in the present specification, the same components have the same numbers as possible, even if they are displayed on different drawings. In addition, in the description of the present invention, when it is determined that detailed descriptions of related known technologies may unnecessarily obscure the subject matter of the present invention, detailed descriptions thereof will be omitted.

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

1 is a view showing a vessel according to an embodiment of the present invention.

1, the ship 1 according to an embodiment of the present invention includes a cargo storage tank 10, a manifold 20, an evaporation gas discharge line 33, a branch line 34 .

In this embodiment, the ship 1 may be made of an LNG-FSRU line that carries LNG while including an LNG floating storage and regasfication unit (FSRU), and the outside is a cargo provided at a shipping location It may be made of a supply tank (not shown), but is not limited thereto, and for convenience of explanation and understanding, the vessel is an LNG-FSRU line, and the outside is a cargo supply tank provided at a shipping location, for example. do. Here, the shipping location may be an LNG carrier that receives and transports LNG.

In this embodiment, when the ship 1 unloads cargo, since the cargo is discharged from the cargo storage tank 10 of the LNG-FSRU line, there is little risk of newly generating evaporation gas, while cargo that forms a limited space during shipment Since the internal pressure of the cargo storage tank 10 may be increased due to the already generated boil-off gas and the newly generated boil-off gas due to the cargo flowing into the storage tank 10, the cargo storage tank 10 may be generated. The manifold 20, branch line 34, and the like, which will be described later, may be used to discharge the boil-off gas.

Specifically, the cargo storage tank 10 is provided on the ship 1 to store cargo. Here, the cargo may be liquefied gas, such as liquefied natural gas (Liquefied Natural Gas), liquefied petroleum gas (Liquefied Petroleum Gas).

Hereinafter, in the present specification, liquefied gas as a cargo may be used in a sense to encompass all gas fuels that are generally stored in a liquid state, such as LNG or LPG, ethylene, ammonia, etc. It can be expressed as liquefied gas. Evaporative gas can be applied as well.

In addition, the cargo storage tank 10 must store cargo in a liquid state, wherein the cargo storage tank 10 may have a pressure tank shape. In addition, a support (not shown) may be provided at a lower portion of the cargo storage tank 10 so that the cargo storage tank 10 may be supported inside the ship 1. Such a support can reduce the lateral and longitudinal movements of the cargo storage tank 10. The cargo storage tank 10 may be provided independently of the hull (not shown), but, of course, may be provided integrally.

The manifold 20 is configured to pass cargo from the cargo storage tank 10 to the outside or to supply fuel to the cargo storage tank 10 from the outside, and a loading line 31 for loading cargo And an unloading line 32 that unloads the cargo of the cargo storage tank 10 to the outside, so that cargo can pass between the outside and the cargo storage tank 10.

For example, when a plurality of cargo storage tanks 10 are provided, they are connected to the manifold 20 so that cargo is loaded or unloaded to each cargo storage tank 10, and for this purpose, a loading line 31 and The unloading line 32 is connected to the manifold 20, as well as the evaporation gas discharge line 33 is connected to the manifold 20, the cargo to the plurality of cargo storage tanks 10 through the manifold 20 This can be loaded or unloaded, and the exhaust gas can be moved.

In addition, cargo may be branched through the manifold 20 to load or unload cargo into the plurality of cargo storage tanks 10. At this time, a valve (not shown) is provided on each line so that the movement of the cargo can be controlled by adjusting the opening of the valve. That is, a movement path of the cargo may be formed through the manifold 20.

The evaporation gas discharge line 33 is connected to the outside through the manifold 20 from the cargo storage tank 10 and discharges the vaporized gas generated in the cargo storage tank 10 when loading the cargo.

Here, if the internal pressure of the cargo storage tank 10 is P1 and the internal pressure of the cargo supply tank provided outside to receive cargo from the cargo storage tank 10 is P2, P1 is made higher than P2. Accordingly, the boil-off gas discharge line 33 can transfer the boil-off gas to the outside without pressurization by using a differential pressure between the cargo storage tank 10 and the outside.

For example, the evaporation gas discharge line 33 may include a main line 33A, a first line 33B, and a second line 33C.

The main line (33A) is made of a doorway connected from the cargo storage tank (10), the first line (33B) is branched from the main line (33A) to join the manifold (20) compressor to compress the evaporation gas ( 35) may be provided. In addition, the second line 33C is branched from the main line 33A to be spaced apart from the first line 33B, joined to the manifold 20, and the branch line 34 can be branched.

In addition, the auxiliary line 37, which is bypassed at the front end of the compressor 35 on the first line 33B, is for protecting the compressor 35. For example, a part of the evaporation gas when a problem occurs due to the overload of the compressor 35, etc. By allowing the compressor 35 to be bypassed, the branch line 34 can be distinguished. That is, the auxiliary line 37 is used for preventing surge, and the discharge of the evaporated gas may be determined according to the size of the evaporated gas discharge line 33.

As mentioned above, a compressor 35 is provided on the first line 33B for compressing the evaporation gas, and the compressor 35 further increases the pressure of the evaporation gas to collect the cargo discharged from the cargo storage tank 10. Although it can be quickly moved to the cargo supply tank, a pressure-reducing valve (not shown) is provided downstream of the compressor 35 on the vaporization gas discharge line 33 to prevent an increase in the internal pressure of the cargo supply tank receiving the vaporized gas. Can be. In this embodiment, while using the difference in the internal pressure of the tank without driving the compressor 35 and the pressure reducing valve, the discharge amount of the evaporated gas can be controlled and discharged through the branch line 34.

At this time, the flow rate of the evaporation gas exiting the evaporation gas discharge line 33 is not controlled, and a block valve 36 is provided on the evaporation gas discharge line 33 to control whether the evaporation gas is discharged.

Specifically, the ship 1 is made of LNG-FSRU line, and the evaporation gas discharge line 33 may be made larger than a size capable of measuring the amount of evaporation gas discharged (for example, a diameter of 600 mm). In this case, when the ship 1 is used for transporting LNG, the amount of the evaporated gas discharged through the evaporated gas discharge line 33 is constant, so that the size of the evaporated gas discharge line 33 is large (for example, the diameter is It can be made of a size that can not measure the amount of evaporated gas emissions as 600mm). On the other hand, when the ship 1 is supplied with LNG used as an FSRU, the amount of loading and unloading needs to be adjusted according to the external type (size, size, etc.).

However, the diameter of the evaporation gas discharge line 33 is large in order to combine the FSRU while achieving the rapid discharge of evaporation gas, and it is difficult to control the discharge amount of the evaporation gas through the evaporation gas discharge line 33.

The branch line 34 is a configuration provided to solve the difficulty of controlling the amount of evaporated gas discharge according to the size of the evaporated gas discharge line 33, and is branched from the evaporated gas discharge line 33 and connected to the manifold 20. . At this time, the amount of the evaporated gas discharged is not made to the size of the evaporated gas discharge line 33, compared to the diameter of the evaporated gas discharge line 33, smaller than 1/2 to 2/3, for example, 400 mm The branch line 34 may be formed to form a diameter.

That is, the final discharge of the boil-off gas is via the manifold 20, but the manifold 20 does not consist of one line, but the loading line 31, unloading line 32, and boil-off gas discharge line 33 It is possible to control such that a plurality of lines are simultaneously used depending on the amount of cargo to be loaded and unloaded, each being branched into a plurality.

Accordingly, the cargo and the evaporated gas moving to the manifold 20 are determined by the diameters of the loading line 31, the unloading line 32, and the evaporated gas discharge line 33 connected to the front end of the manifold 20. Can be decided.

Here, since the diameter of the evaporation gas discharge line 33 is made of a size that is difficult to control the evaporation gas discharge amount to combine FSRU and LNG transportation, the discharge amount of the evaporation gas through the branch line 34 is reduced. Can be adjusted.

Accordingly, the branch line 34 may be made of a small size in comparison with the diameter of the evaporation gas discharge line 33, that is, a size capable of measuring the discharge amount of the evaporation gas.

The branch line 34 is branched from the boil-off gas discharge line 33, but joins at the manifold 20, so the amount of boil-off gas moving to the manifold 20 determines the size and boil-off gas of the branch line 34. It can be determined by the amount recovered.

Accordingly, it is possible to measure the discharge amount of the evaporated gas through the branch line 34, as well as to control the amount discharged. To this end, a control valve 34A and a flow meter 34B may be provided in the branch line 34.

Here, the control valve (34A) can adjust the flow rate of the evaporated gas transmitted to the outside through the manifold (20). In addition, the control valve 34A may control the flow rate of the evaporated gas by receiving a signal from the flowmeter 34B while maintaining the pressure of the cargo storage tank 10 higher than the external pressure. At this time, the cargo storage tank 10 is provided with a pressure gauge (not shown), and the control valve 34A can be adjusted according to the pressure state inside the cargo storage tank 10.

As described above, in the present embodiment, the evaporation gas is discharged while the evaporation gas is discharged while the evaporation gas is discharged by using the internal pressure of the tank provided in the vessel 1 made of the LNG-FSRU line without operating the compressor 35. It is smaller in size than the evaporation gas discharge line, so it is possible to control the evaporation gas emission amount through a branch line that can control the amount of emissions. Work can be done conveniently.

Although the present invention has been described in detail through specific examples, the present invention is specifically for describing the present invention, and the present invention is not limited to this, and by those skilled in the art within the technical spirit of the present invention. It will be apparent that the modification and improvement are possible.

All simple modifications or changes of the present invention belong to the scope of the present invention, and the specific protection scope of the present invention will be clarified by the appended claims.

1: Ship 10: Cargo storage tank
20: Manifold 31: Loading line
32: Unloading line 33: Evaporative gas discharge line
33A: main line 33B: first line
33C: second line 34: branch line
34A: Control valve 34B: Flow meter
35: compressor 36: block valve
37: auxiliary line

Claims (10)

A cargo storage tank for storing cargo;
A manifold that is connected to a loading line for loading the cargo and an unloading line for unloading cargo of the cargo storage tank to the outside, so that cargo passes between the external and the cargo storage tank;
An evaporation gas discharge line connected from the cargo storage tank to the outside through the manifold and discharging evaporation gas generated in the cargo storage tank when loading the cargo; And
And a branch line branched from the boil-off gas discharge line and connected to the manifold.
The boil-off gas discharged through the boil-off gas discharge line is transmitted to the outside without pressure by the differential pressure between the cargo storage tank and the outside, and the discharge amount is controlled via the branch line,
The evaporation gas discharge line,
A main line connected from the cargo storage tank;
A first line branched from the main line, joined to the manifold, and provided with a compressor for compressing the boil-off gas; And
And a second line branched from the main line to be spaced apart from the first line, joined to the manifold, and branched from the branch line. delete According to claim 1,
The diameter of the branch line is characterized in that the vessel made of 1/2 to 2/3 smaller than the diameter of the evaporation gas discharge line. According to claim 1,
A ship characterized in that the auxiliary line is further provided to bypass the compressor after being branched from the evaporation gas discharge line and joining the evaporation gas discharge line. According to claim 1, In the branch line,
Ship characterized in that the control valve and the flow meter is provided. According to claim 5, The control valve,
Vessel characterized in that to control the flow rate of the evaporation gas delivered to the outside through the manifold. According to claim 5, The control valve,
A vessel characterized in that the flow rate of the evaporation gas is adjusted while maintaining the pressure of the cargo storage tank higher than the external pressure. According to claim 1, The evaporation gas discharge line,
A vessel characterized in that a block valve is provided to control whether or not the boil-off gas is discharged. The method of claim 1, wherein the outside,
A ship characterized in that it is a cargo supply tank provided at the place of shipment. According to claim 1, The cargo storage tank,
A vessel characterized by consisting of a tank provided on the LNG-FSRU line.

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