KR20150083665A - Vent master unit and lng carrier having the same - Google Patents

Abstract

An LNG carrier is disclosed. According to the present invention, the LNG carrier comprises: a cargo vent master arranged in a hull to discharge gas generated in a cargo tank; and a high-pressure gas vent master arranged in the hull, discharging fuel gas on a supply line of fuel gas supplied to a high-pressure gas injection engine, and discharging fuel gas through a separate line from a vent line connected to the cargo vent master.

Description

(VENT MASTER UNIT AND LNG CARRIER HAVING THE SAME)

[0001] The present invention relates to a vent master unit and a liquefied natural gas carrier having the same, and more particularly, to a vent gas master in a fuel gas supply line connected to a high pressure gas distribution engine separately from a cargo vent master for discharging gas in a cargo tank Pressure gas vent master and a liquefied natural gas carrier having the high-pressure gas vent master.

Recently, interest in liquefied fuel gas, which is much cheaper than that of heavy oil, but which is a clean energy source, for example, propulsion engines using LNG (or LPG, DME) as fuel is increasing due to the rise in oil prices.

As a marine engine capable of obtaining propulsion power using liquefied fuel gas as a fuel, there is a high pressure gas injection engine such as ME-GI (Gas Injection Engine of Man B & W).

Such an ME-GI engine can be installed in a liquefied natural gas carrier that stores LNG (Liquefied Natural Gas) in a cryogenic storage tank and transports it. In this case, natural gas is used as a fuel. Depending on the load A high gas supply pressure of about 150 to 300 bara (absolute pressure) is required.

In order to apply the ME-GI engine to general merchant vessels without an LNG storage tank, an LNG fuel tank capable of receiving LNG as fuel is installed.

If the liquefaction system is installed in the ME-GI engine, it will be possible to use boil-off gas (BOG) as a fuel depending on the change in gas and fuel oil prices and the degree of regulation of the exhaust gas, There is an advantage in that the gas can be re-liquefied and sent to the storage tank and the heavy fuel oil (HFO) can be used.

In particular, LNG can be easily vaporized and used as fuel when it passes through a specific regulatory environment related to environmental pollution. It can be used as a main engine of a liquefied natural gas carrier in the future as the next generation environmentally friendly engine reaches 50% efficiency .

A fuel gas supply system must be provided to supply the ME-GI engine with LNG (or evaporative gas) contained in the LNG storage tank (or LNG fuel tank) as fuel.

Examples of such a fuel gas supply system are disclosed in International Patent Publication Nos. WO 2009/011497 and WO 2009/136793.

In International Patent Publication No. WO 2009/011497, LNG discharged from an LNG storage tank is vaporized in a vaporizer and then supplied to a high-pressure gas injection engine such as an ME-GI engine, and evaporation gas discharged from an LNG storage tank is supplied to the vaporizer Discloses a fuel gas supply system for performing liquefaction by heat exchange with LNG.

In International Patent Publication No. WO 2009/136793, LNG discharged from an LNG storage tank is compressed by a high-pressure pump, and then evaporated in an evaporator to be supplied to a gas engine such as an ME-GI engine. Gas is compressed in an evaporative gas compressor, re-liquefied in a cryogenic heat exchanger, mixed with LNG supplied to a high-pressure pump, and supplied to a gas engine.

Such a fuel gas supply system is an essential element for supplying the fuel gas of the temperature and pressure required by the engine, that is, the state required by the engine. The ME-GI engine changes the load according to the output required by the engine. The specifications of various components constituting the fuel gas supply system are determined so that the engine load can follow smoothly over time.

On the other hand, when a high-pressure gas injection engine such as an ME-GI engine is actually applied to a liquefied natural gas carrier, a fuel gas supply line for supplying the fuel gas to the high-pressure gas injection engine is required. bara (absolute pressure) of fuel gas flows.

In addition, there is a need for a gas valve train (also known as a gas valve unit) that adjusts the pressure of the fuel gas to meet the required pressure in the high pressure gas injection engine and quickly and reliably blocks the supply of fuel gas. There is no actual application of these gas valve trains to vessels equipped with high-pressure gas injection engines such as the ME-GI engine.

Conventional liquefied natural gas carriers have a trunk deck provided with a vent master that releases gas inside the cargo tanks to regulate the pressure in the cargo tanks.

When the high-pressure gas injection engine is actually applied to a liquefied natural gas carrier, a high-pressure compressor for compressing the fuel gas to high pressure in addition to the gas valve train described above is required.

In particular, when venting equipment such as the ME-GI engine, gas valve train, high-pressure compressor, and fuel gas supply line, the gas vented in the equipment and the fuel gas supply line described above is different from the gas discharged from the cargo tank, Therefore, a countermeasure is required.

In addition, since the gas vented through the fuel gas supply line is a high-pressure gas, a large noise is generated, and a countermeasure is required.

The above-described technical structure is a background technique for assisting the understanding of the present invention, and does not mean the prior art widely known in the technical field to which the present invention belongs.

Korean Patent Laid-Open Publication No. 2012-0125129 (Daewoo Shipbuilding & Marine Engineering) 2012.11.14.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a liquefied gas engine having a fuel gas venting master for venting high-pressure gas through a line separate from a line of a cargo vent master for venting gas in a cargo tank when the high- To provide a natural gas carrier.

According to an aspect of the present invention, there is provided a cargo vent master which is provided on a hull and discharges gas generated from a cargo tank; And a high pressure gas vent master provided in the hull and discharging the fuel gas from a supply line of the fuel gas supplied to the high pressure gas injection engine.

The high pressure gas discharged through the high pressure gas vent master may be discharged through a line separate from the vent line connected to the cargo vent master.

The high-pressure gas vent master may discharge the fuel gas through a high-pressure vent line branching from the fuel gas supply line.

The high pressure gas vent master may be provided on top of a trunk deck.

The high pressure gas vent master may be provided in the trunk deck in a peripheral region of the cargo vent master disposed closest to the engine room.

The high pressure gas vent master may be provided in a set with the cargo vent master.

Further comprising a main engine gas control unit for controlling a liquefied gas which is a fuel gas supplied to the high pressure gas injection engine, wherein the high pressure gas vent master discharges the fuel gas through a first high pressure vent line, which is a vent line of the gas control unit .

The high pressure gas vent master may discharge the fuel gas through a second high pressure vent line connected to a safety valve provided in a high pressure line in a cargo compressor room.

The high pressure gas vent master may discharge the fuel gas through a third high pressure vent line connected to the rear line of the safety valve of the high pressure equipment including the BOG compressor.

And a silencer provided at a leading end of the high-pressure gas vent master.

A part of the fuel gas supply line connected to the high-pressure gas injection engine may be connected to the high-pressure gas injection engine through a coffer dam.

The high-pressure gas injection engine may include an ME-GI engine.

According to another aspect of the present invention, there is provided a liquefied natural gas carrier which is provided on a hull of a high pressure gas vent master for discharging the fuel gas from a fuel gas supply line supplied to a high pressure gas injection engine .

The high pressure gas vent master may discharge the fuel gas supplied through a line separate from the vent line connected to the cargo vent master provided in the trunk deck.

According to another aspect of the present invention, there is provided a cargo vent master which is provided in a hull and discharges gas generated from the cargo tank; And a high pressure gas vent master provided in the hull and discharging the fuel gas from a supply line of the fuel gas supplied to the high pressure gas injection engine.

Embodiments of the present invention can be applied to a high pressure gas injection engine by discharging high pressure equipment and high pressure gas discharged from a fuel gas supply line through a fuel gas venting master separate from a cargo venting master for venting gas in a cargo tank It is possible to discharge stably and efficiently without affecting the flow of gas bet on the cargo tank.

1 is a side view schematically illustrating a liquefied natural gas carrier according to an embodiment of the present invention.
Fig. 2 is a layout diagram schematically showing a state in which a main portion of the present embodiment is provided in a cargo tank disposed closest to the engine room in Fig. 1. Fig.
3 is a use state diagram of this embodiment.

In order to fully understand the present invention, operational advantages of the present invention, and objects achieved by the practice of the present invention, reference should be made to the accompanying drawings and the accompanying drawings which illustrate preferred embodiments of the present invention.

Hereinafter, the present invention will be described in detail with reference to the preferred embodiments of the present invention with reference to the accompanying drawings. Like reference symbols in the drawings denote like elements.

However, the present invention is not limited to a marine structure as well as a vessel having a high-pressure gas vent master installed separately from the cargo vent master by applying the ME-GI engine, which is a high-pressure gas injection engine.

1 is a side view schematically illustrating a liquefied natural gas carrier according to an embodiment of the present invention.

The present embodiment can select a liquefied natural gas carrier as a middle- or large-sized ship having a high-pressure gas injection engine 20 in which liquefied gas is used as fuel in the engine room 10.

As shown in FIG. 1, a plurality of LNG tanks 30, in which liquefied natural gas (LNG) is stored, are provided on the liquefied natural gas carrier. Since the LNG stored in the LNG tank 30 is stored at about -163 ° C, which is the vaporization temperature at normal pressure, when the heat is transferred to the LNG, the LNG in the liquid state is vaporized and the boil off gas (BOG) . The generated BOG may be supplied to the high-pressure gas injection engine 20 and used as fuel for driving the high-pressure gas injection engine 20, and may be supplied to the cargo vent master 60 and discharged to the atmosphere.

Meanwhile, the LNG stored in the LNG tank 30 may be vaporized through the forced vaporizer and used as fuel (liquefied).

The LNG tank 30 shown in FIG. 1 is a membrane type. In the case of a membrane type LNG tank, when a cold LNG tank is continuously installed, the temperature of the steel between the LNG tank 30 and the LNG tank 30 suddenly drops and brittle fracture Can happen.

In order to prevent this, a space called a cofferdam 40 is placed between the LNG tanks 30 to prevent the LNG from being damaged at low temperature. The coffer dam 40 is heated by a heating device to a temperature of 5 ° C or higher maintain. The copper dam (40) is provided with a void space (23) between a pair of bulkheads (21).

1, an engine room 10 is provided at a stern portion of a liquefied natural gas transportation line, and a high-pressure gas injection engine 20 using liquefied gas as a fuel is provided in the engine room 10. In this embodiment, the high-pressure gas injection engine 20 uses natural gas as the fuel, and it may be an ME-GI engine which requires a high-pressure gas supply pressure depending on the load.

The ME-GI engine compresses LNG (or LPG, DME) to high pressure (150 to 600 bar) and then injects and burns it. It is also called high pressure gas injection engine and injects diesel oil and liquefied gas selectively into the engine. Can be promoted.

In this embodiment, since the high-pressure gas injection engine 20 is adopted as the main engine in the present embodiment, the fuel gas supplied to the high-pressure gas injection engine 20 is a high-pressure fuel gas supplied to the fuel gas supply line 50, Pressure gas injection engine 20, and the main engine gas control unit 110 are required to be vented.

The present embodiment can perform such venting through the high-pressure gas vent master 70 shown in FIG. 1, rather than the cargo vent master 60, and the high- A silencer (80) may be provided to reduce noise. The high-pressure gas vent master 70 and the silencer 80 will be described in detail with reference to FIG.

On the other hand, on the upper side of the engine room 10, a housing 90 is provided as shown in Fig. The residence 90 is provided with a crew room and a steering column, and the residence 90 occupies most of the area in the width direction of the stern section hull.

Therefore, when the fuel gas supply line 50 for supplying the liquefied gas from the outside of the engine room 10 to the high-pressure gas injection engine 20 is designed in the liquefied natural gas carrier, The fuel gas supply line 50 is exposed to the outside and there is a risk of damage.

The present embodiment connects the fuel gas supply line 50 to the engine room 10 through the coffer dam 40 disposed closest to the engine room 10 to optimally arrange the fuel gas supply line 50 .

On the other hand, as shown in FIG. 1, a plurality of cargo spaces 100 are provided in a trunk deck (TD) of a liquefied natural gas carrier. The cargo room 100 which is disposed closest to the housing 90 of the plurality of cargo spaces 100 is a cargo compressor room provided with an electric motor and a cargo compressor and the cargo gear locker And a dry powder station, and finally a storage compartment 100 in which a dry powder and a companion way are provided.

As shown in FIG. 1, the cargo compressor room is disposed closest to the engine room 10, and is larger in size than the other cargo room 100, so that there is plenty of room inside. In addition, the cargo compressor room is a non-hazardous area, unlike the engine room 10.

The present embodiment is characterized in that a main engine gas control unit 110 (see FIG. 3) for controlling the liquefied gas supplied to the high pressure gas injection engine 20 is provided in the cargo compressor room so as to be connected to the engine room 10 A problem caused by installing a gas valve train can be solved in advance.

That is, this embodiment controls the pressure of the liquefied gas supplied to the high-pressure gas injection engine 20 when the liquefied gas is used as fuel for the high-pressure gas injection engine 20, By designing the engine gas control unit 110 (refer to FIG. 3) to be provided in the cargo compartment, not in the engine room 10, it is possible to compensate for the disadvantages associated with the gas valve train that may occur when liquefied gas is used as propelling fuel.

Specifically, the engine room is classified as a danger zone. In a conventional small-sized ship, a gas valve train is provided separately in the engine room and in a gas valve train room completely separated from other rooms in the engine room. Gas valve train rooms shall be gas tight and electrical equipment located in the gas valve train room shall perform ATEX requirements for hazardous area Zone 1.

In addition, the inlet of the gas valve train room must be equipped with an air lock, which must be large enough for one person to pass.

In a small-sized ship using liquefied gas as fuel, there are many restrictions due to the gas valve train. In the case of designing to provide the gas valve train in the engine room while using the liquefied gas as fuel in the middle- Gas tanks, air locks, and other devices must be considered, which leads to a complicated design and an increase in cost.

In this embodiment, the main engine gas control unit 110 can be provided in the cargo compartment because the ME-GI engine employed as the high-pressure gas injection engine 20 is a high-pressure (150 to 600) engine.

In this embodiment, since the liquefied gas supplied to the high-pressure gas injection engine 20 has a pressure of 250 to 320 bar, even if the main engine gas control unit 110 is installed far away from the high-pressure gas injection engine 20, Since the pressure of the liquefied gas can be regulated by the pressure required by the engine 20.

In the present embodiment, the main engine gas control unit 110 may be provided in the cargo compartment 100 as a pair (see FIG. 3), and each main engine gas control unit 110 may include a high- (Not shown).

Also, in this embodiment, the main engine gas control unit 110 may be a gas valve train or a gas valve unit.

Fig. 2 is a layout diagram schematically showing a state in which a main portion of the present embodiment is provided in a cargo tank disposed closest to the engine room in Fig. 1. Fig.

2, the high pressure gas vent master 70 is provided separately from the cargo vent master 60 for discharging the gas of the LNG tank 30, and the high pressure gas vent master 70 The gas can be vented through the high-pressure gas injection engine 20 or the high-pressure equipment or the fuel gas supply line 50 including the main engine gas control unit 110 or the high-pressure compressor.

2, the high-pressure vent line 120 connected to the high-pressure gas vent master 70 in this embodiment is provided as an independent line that is not connected to the venting line for venting the gas of the LNG tank 30 . Since the gas discharged through the high-pressure vent line 120 is a high-pressure gas, the state of the gas discharged from the LNG tank 30 is different from that of the gas discharged from the LNG tank 30. Therefore, So as to improve stability.

In this embodiment, the high-pressure gas vent master 70 may be provided separately from the cargo vent master 60 on the upper surface of the trunk deck TD and may be provided integrally with the cargo vent master 60 .

That is, after the cargo vent master 60 and the high pressure gas vent master 70 are separately manufactured, the cargo vent master 60 and the high pressure gas vent master 70 are bracketed before being installed in the trunk deck TD And the cargo vent master 60 and the high pressure gas vent master 70 can be installed in the trunk deck TD together.

In this embodiment, the high-pressure vent line 120 is branched in the fuel gas supply line 50, and the high-pressure vent line 120 is connected to the high-pressure gas vent master 70 to discharge the gas.

The present embodiment further includes a first high-pressure vent line 121, which is a vent line in which one end is connected to the main engine gas control unit 110 (see Fig. 3) and the other end is connected to the high- And a second high-pressure vent line 122, one end of which is connected to a safety valve provided in a high-pressure line in a cargo compressor room and the other end is connected to a high-pressure gas vent master 70, The fuel gas may be exhausted through the exhaust passage. In this embodiment, the high pressure line provided inside the cargo compressor room may be a line through which the compressed fluid compressed at a high pressure is discharged from the high pressure compressor.

Further, the present embodiment is characterized in that the fuel gas is supplied through the third high-pressure vent line 123, one end of which is connected to the rear end line of the safety valve of the high-pressure equipment including the BOG compressor and the other end is connected to the second high- . In this embodiment, the third high-pressure vent line 123 may be provided with an on-off valve 130, which may be a check valve for preventing backflow of the discharged high-pressure gas.

In this embodiment, the silencer 80 may be provided on the high-pressure vent line 120 to reduce the noise of gas discharged at a high pressure. In this embodiment, the muffler 80 may be provided in the first high-pressure vent line 121 and the second high-pressure vent line 122, respectively.

The open / close valve 130 may be provided in the high-pressure vent line 120 of the muffler 80.

A gas dome 140 and a liquid dome 150 are provided at the rear of the cargo vent master 60. The gas dome 140 and the liquid dome 150 are provided one by one for each LNG tank 30. The gas dome 140 is provided with a pipe for discharging or introducing gas inside the LNG tank 30 and an upper end of a pump tower is fixed to the liquid dome 150.

3 is a use state diagram of this embodiment. Hereinafter, the use state of the present embodiment will be briefly described with reference to FIG.

3, the high-pressure gas vent master 70 and the silencer 80 are connected to a fuel gas supply line (not shown) for connecting the main engine gas control unit 110 and the high-pressure gas injection engine 20 Pressure vent line 120 that branches off from the high-pressure vent line 50.

The fuel gas supply line 50 disposed from the cargo compressor room, which is the closest to the engine room 10 to the cofferdam 40, may be provided as a single pipe rather than a double pipe.

The fuel gas supply line 50 connecting the main engine gas control unit 110 and the high-pressure gas injection engine 20 in this embodiment may be provided with a pair as shown in FIG. That is, one fuel gas supply line 50 is connected to each of the main engine gas control units 110, and the fuel (not shown) connected to each high-pressure gas injection engine 20 in each main engine gas control unit 110 The gas supply lines 50 may be provided in pairs for stable and efficient fuel supply.

As described above, according to the present embodiment, when the high-pressure gas injection engine is applied to the solid line, the high-pressure equipment and the high-pressure gas discharged from the fuel gas supply line are separated from the cargo venting master, It is possible to discharge stably and efficiently without affecting the flow of gas bet on the cargo tank.

In addition, a silencer may be provided in the high-pressure vent line of the high-pressure gas vent master to reduce the noise generated due to the discharge of the high-pressure gas.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Accordingly, such modifications or variations are intended to fall within the scope of the appended claims.

1: liquefied natural gas carrier 10: engine room
20: High-pressure gas injection engine 30: LNG tank
40: Copper dam 50: Fuel gas supply line
60: Cargo Bent Master 70: High Pressure Gas Vented Master
80: Silencer 90: Residential District
100: Cargo room 110: Main engine gas control part
120: high-pressure vent line 121: first high-pressure vent line
122: second high-pressure vent line 123: third high-pressure vent line
130: opening / closing valve 140: gas dome
150: liquid dome TD: trunk deck

Claims (15)

A cargo vent master installed on the hull to discharge gas generated from the cargo tank; And
And a high pressure gas vent master provided in the hull for discharging the fuel gas from a supply line of the fuel gas supplied to the high pressure gas injection engine. The method according to claim 1,
Wherein the high pressure gas discharged through the high pressure gas vent master is discharged through a line separate from the vent line connected to the cargo vent master. The method according to claim 1,
Wherein the high pressure gas vent master discharges the fuel gas through a high pressure vent line that branches off from the fuel gas supply line. The method of claim 3,
Wherein the high pressure gas vent master is provided on top of a trunk deck. The method of claim 4,
Wherein said high pressure gas vent master is provided in said trunk deck in a peripheral region of said cargo vent master disposed closest to said engine compartment. The method according to claim 1,
Wherein the high pressure gas vent master is provided in a set with the cargo vent master. The method according to claim 1,
Further comprising a main engine gas control section for controlling liquefied gas which is a fuel gas supplied to the high-pressure gas injection engine,
Wherein the high pressure gas vent master discharges the fuel gas through a first high pressure vent line which is a vent line of the gas control unit. The method according to claim 1,
Wherein the high pressure gas vent master discharges the fuel gas through a second high pressure vent line connected to a safety valve provided in a high pressure line in a cargo compressor room. The method according to claim 1,
Wherein the high pressure gas vent master discharges the fuel gas through a third high pressure vent line connected to a rear line of a safety valve of a high pressure equipment including a BOG compressor. The method according to claim 1,
And a silencer provided at a leading end of the high-pressure gas vent master. The method according to claim 1,
And a part of the fuel gas supply line connected to the high pressure gas injection engine is connected to the high pressure gas injection engine through a coffer dam. The method according to claim 1,
Wherein the high pressure gas injection engine comprises an ME-GI engine. And a high pressure gas vent master for discharging the fuel gas from a fuel gas supply line supplied to the high pressure gas injection engine is provided on the hull. 14. The method of claim 13,
Wherein the high pressure gas vent master discharges the fuel gas supplied through a line separate from a vent line connected to a cargo vent master provided in the trunk deck. A cargo vent master installed on the hull to discharge gas generated from the cargo tank; And
And a high pressure gas vent master which is provided in the hull and discharges the fuel gas from a supply line of the fuel gas supplied to the high pressure gas injection engine.

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