KR20240031530A - Liquefied Gas Fuel Supply System For Ship - Google Patents

Abstract

The ship's liquefied gas fuel supply system is launched. The liquefied gas fuel supply system for ships of the present invention includes an engine room where a propulsion engine of a ship supplied with liquefied gas as fuel is placed; A cargo compressor room provided on the upper deck and in which a fuel supply unit is arranged to supply liquefied gas according to the fuel supply conditions required by the propulsion engine; A GVT room provided adjacent to the engine room at the upper part of the deck and where a GVT (Gas Valve Train) including a plurality of valves for controlling fuel supply from the fuel supply unit to the propulsion engine is disposed; and a vent line connected from the GVT, wherein when the gas fuel operation of the propulsion engine is stopped (Gas Stop), the gas fuel supply is blocked by the GVT and the remaining fuel supply pipe between the GVT and the propulsion engine is The gas fuel is discharged into the vent line.

Description

Liquefied Gas Fuel Supply System for Ship}

The present invention relates to a liquefied gas fuel supply system for ships, and more specifically, to a separate GVT room in which a GVT (Gas Valve Train) is placed adjacent to the engine room in a ship equipped with a propulsion engine supplied with liquefied gas as fuel. When the gas fuel operation of the propulsion engine is stopped (Gas Stop), the supply of gas fuel is blocked by the GVT and the gas fuel remaining in the fuel supply pipe between the GVT and the propulsion engine is discharged to the vent line. It's about the fuel supply system.

Conventionally, ships such as bulk carriers, container ships, and passenger ships generally used a fuel supply system that used liquid fuels such as heavy fuel oil (HFO) such as bunker C oil and diesel oil (MDO) as propulsion fuel.

When burning heavy oil, etc. used as fuel in such a conventional fuel supply system, there is a problem of serious environmental pollution due to various harmful substances contained in the exhaust gas. As demands to prevent environmental pollution are gradually strengthening worldwide, regulations on propulsion devices that use heavy oil as fuel oil are also being strengthened, and the cost of satisfying these regulations is gradually increasing.

The International Maritime Organization (IMO) predicts that global greenhouse gas emissions from ships will increase from 2.7% in 2007 to 12-18% in 2050, and the MARPOL Convention is being adopted to prevent air pollution from ships. By adding 'Air Pollution Prevention' to Annex VI, SOx (sulfuric acid), NOx (nitrogen oxides), and ODS (ozone layer depletion causing substances) have been designated as regulated substances.

In addition, ship emission regulations are applied to the ECA (Emission Control Area), and the sulfur content in ship fuel has been strengthened to 0.1% since 2010 for all ships entering the ECA.

Accordingly, the technology of using liquefied gases such as LNG, LPG, CNG, and DME as ship fuel has recently been in the spotlight. In particular, LNG can be an eco-friendly fuel because its carbon dioxide emissions are more than 20% lower than that of coal-based fuels such as bunker C oil, and it emits almost no nitrogen oxides and sulfur oxides, which are the main causes of air pollution.

Recently, with the strengthening of international exhaust gas emission regulations, the adoption of fuel supply systems that use LPG or LNG and the boil-off gas generated therefrom as propulsion fuel is increasing not only in LPG or LNG carriers but also in general ships.

Representative marine engines that can obtain propulsion power using LNG as fuel include the ME-GI engine or the DFDE (Dual Fuel Diesel Electric) engine. The ME-GI engine or DFDE (Dual Fuel Diesel Electric) engine is a gas injection engine that compresses LNG and then injects it for combustion. In particular, the ME-GI engine compresses LNG to a high pressure of around 300 bar and then injects it for combustion, so it is called a high-pressure gas injection engine.

High-pressure gas injection engines, such as the ME-GI engine, are preferred as propulsion engines for ships because the problem of methane slip, in which methane, the main component of LNG, is incompletely burned and released into the atmosphere through exhaust gas, is less than that of low-pressure gas injection engines. there is. When methane is released into the atmosphere, it can cause a greater greenhouse effect than carbon dioxide.

In the case of a gas injection engine supplied with compressible fluid, i.e. gas fuel, whose volume changes greatly according to pressure changes, the fuel supply pressure is slightly lower than the engine's fuel supply pressure to prevent cavitation by supplying sufficient fuel even when the engine load changes. Fill gas fuel at high pressure to maintain the pressure in the fuel supply pipe.

Figure 1 schematically shows a gas supply system in a ship equipped with a conventional gas injection engine as a propulsion engine.

As shown in FIG. 1, the fuel supply system 10 is disposed in the cargo compressor room (CCR) provided on the upper deck, and the propulsion engine ( The fuel supply pipe (L) is connected from the fuel supply system to ME). The fuel supply piping is equipped with a gas valve train (30) to control the supply of gas fuel and a master gas valve (20) to block the supply of gas fuel from the fuel supply system. , these devices are provided in the cargo compressor room.

However, in the IGC Code (International code for the construction and equipment of ships carrying liquefied gases in bulk), which is an international standard for the structure and equipment of liquefied gas carriers established by the International Maritime Organization (IMO), the fuel connected to the engine room after the master gas valve is It is required that the supply piping be arranged as a double wall pipe. Currently, there is no double wall type gas valve train, and when the master gas valve and the gas valve train are placed close to each other, installation of a double pipe after the gas valve train is allowed. In order to meet the IGC Code, the master gas valve (20) is required. and gas valve train (30) are all located close to each other in the cargo compressor room.

However, during ship operation, when gas fuel operation is stopped and fuel is switched, or when a trip or engine is stopped, the master gas valve must be closed and the gas fuel remaining in the engine and the double pipe must be vented. The pipe length is long and the pressure of the gas fuel must be vented. The higher the value, the greater the amount of gaseous fuel emitted, so the greenhouse effect and adverse environmental impacts caused by gaseous fuel vented when gas operation is stopped have been consistently pointed out, especially for high-pressure gas injection engines.

The present invention is intended to solve this problem and proposes a method to reduce the amount of gas fuel emitted when gas fuel operation is stopped in a ship using gas fuel.

According to one aspect of the present invention for solving the above-described problem, an engine room where a propulsion engine of a ship supplied with liquefied gas as fuel is placed;

A cargo compressor room provided on the upper deck and in which a fuel supply unit is arranged to supply liquefied gas according to the fuel supply conditions required by the propulsion engine;

A GVT room provided adjacent to the engine room at the upper part of the deck and where a GVT (Gas Valve Train) including a plurality of valves for controlling fuel supply from the fuel supply unit to the propulsion engine is disposed; and

Including a vent line connected from the GVT,

When the gas fuel operation of the propulsion engine is stopped (Gas Stop), the gas fuel supply is blocked by the GVT and the gas fuel remaining in the fuel supply pipe between the GVT and the propulsion engine is discharged to the vent line. A liquefied gas fuel supply system for ships is provided.

Preferably, the GVT includes: a first valve disposed between the fuel supply part and the connection part of the vent line; a second valve disposed between the connection portion and the propulsion engine; and a third valve provided in the vent line, wherein the first valve may be operated as a master valve for blocking the supply of gas fuel to the fuel supply pipe.

Preferably, the GVT may further include a fourth valve disposed in a venting pipe connected from a fuel supply pipe at a rear end of the second valve to a vent line at a rear end of the third valve.

Preferably, the GVT room is provided as a separate space from the cargo compressor room between the cargo compressor room and the engine room, and the fuel supply pipe between the GVT room and the propulsion engine is a double wall pipe. It can be prepared by:

Preferably, it may further include an extraction fan provided for ventilation of the GVT room.

Preferably, the propulsion engine may be a dual fuel engine supplied as fuel with LNG and oil compressed to 10 to 350 bar.

Preferably, the GVT receives a control signal from the ship's ECS (Engine control system) to control the supply of gas fuel from the fuel supply unit to the propulsion engine, and receives a control signal from the ship's ESD (Emergency Shutdown System) to supply gas to the propulsion engine. The fuel supply can be cut off.

Preferably, the ship is provided with two propulsion engines, and the GVT room may be provided with two GVTs to control fuel supply to each of the two propulsion engines.

Preferably, the ship may be provided with two propulsion engines and two GVT rooms in which GVTs are arranged to control fuel supply to each of the two propulsion engines.

According to the present invention, in a ship equipped with a propulsion engine supplied with liquefied gas such as LNG, the amount of gaseous fuel discharged from the fuel supply pipe when the gas fuel operation is stopped (Gas Stop) can be significantly reduced, thereby reducing the amount of gaseous fuel caused by ship operation. Greenhouse gas emissions can be reduced.

In addition, while meeting the safety regulations stipulated by the International Maritime Organization, the length of the double pipe can be shortened and the master gas valve previously placed in the cargo compressor room to block the supply of gas fuel can be removed, thereby reducing installation costs.

Figure 1 schematically shows a gas supply system in a ship equipped with a conventional gas injection engine as a propulsion engine.
Figure 2 schematically shows a liquefied gas fuel supply system for a ship according to the first embodiment of the present invention.
Figure 3 schematically shows the ship arrangement structure according to the first embodiment of the present invention.
Figure 4 schematically shows a ship arrangement structure according to a second embodiment of the present invention.

In order to fully understand the operational advantages of the present invention and the objectives achieved by practicing the present invention, reference should be made to the accompanying drawings illustrating preferred embodiments of the present invention and the contents described in the accompanying drawings.

Hereinafter, the structure and operation of a preferred embodiment of the present invention will be described in detail with reference to the attached drawings. Here, in adding reference numerals to components in each drawing, it should be noted that identical components are indicated with the same reference numerals as much as possible, even if they are shown in different drawings.

In the embodiment of the present invention described later, the ship may be any type of ship installed with an engine that can use liquefied gas as fuel for a main engine for propulsion or fuel for a power generation engine. Representative examples include ships with self-propelled capabilities such as LPG carriers, LNG carriers, liquid hydrogen carriers, and LNG RVs (Regasification Vessels), as well as LNG FPSOs (Floating Production Storage Offloading) and LNG FSRUs (Floating Storage Regasification Units). Marine structures that do not have propulsion capabilities but are floating in the sea may also be included.

In addition, this embodiment can be applied to a fuel supply system for all types of liquefied gas that can be liquefied at low temperature and transported, generate boil-off gas in a stored state, and be supplied as fuel for an engine. These liquefied gases are, for example, liquefied petrochemicals such as LNG (Liquefied Natural Gas), LEG (Liquefied Ethane Gas), LPG (Liquefied Petroleum Gas), Liquefied Ethylene Gas, and Liquefied Propylene Gas. It may be gas, ammonia, etc. However, in the examples described later, the application of LNG, one of the representative liquefied gases, will be described as an example.

Figure 2 schematically shows the liquefied gas fuel supply system for a ship according to the first embodiment of the present invention, Figure 3 schematically shows the ship arrangement structure accordingly, and Figure 4 shows the liquefaction of the second embodiment, which is a modification of the first embodiment. The ship arrangement structure according to the gas fuel supply system is schematically shown.

As shown in Figures 2 and 3, the liquefied gas fuel supply system according to the first embodiment of the present invention is located in the engine room (ER) where the propulsion engine (ME) of the ship supplied with liquefied gas is located, and the upper deck. It is provided in the cargo compressor room (CCR), where a fuel supply unit 300 is located to supply liquefied gas according to the fuel supply conditions required by the propulsion engine, and is provided adjacent to the engine room (ER) at the upper deck and is provided from the fuel supply unit. It includes a GVT room (GR) where a GVT (Gas Valve Train) 100 including a plurality of valves for controlling fuel supply to the propulsion engine is placed, and a vent line (VL) connected to the GVT.

The propulsion engine (ME) applied to the ship in this embodiment may be, for example, a dual fuel engine supplied with LNG and oil compressed to 10 to 350 bar as fuel. For example, it may be a ME-GI engine that compresses LNG at a high pressure of about 300 bar and then injects and combusts it, or a ME-GA engine that receives gas fuel compressed at a low pressure of about 10 to 15 bar.

The fuel supply unit 300 is for supplying LNG according to the fuel supply conditions of the propulsion engine. For example, it includes a compression device and a heating device for compressing and heating LNG according to the pressure and temperature required by the propulsion engine. can do. LNG that has passed through the fuel supply section is supplied as fuel for the propulsion engine along the fuel supply pipes (FLa, FLb). Fuel supply from the fuel supply unit to the propulsion engine can be controlled by opening/closing the valves provided in the GVT.

In the present embodiments, the GVT room (GR) where the GVT is placed is located on the upper deck, and the cargo compressor room (CCR) where the fuel supply unit is located between the cargo compressor room (CCR) and the engine room (ER). ) is characterized by being a separate space.

The fuel supply pipe (FLb) between the GVT room and the propulsion engine is a double wall pipe that includes an inner pipe through which gas fuel flows and an outer pipe that surrounds the outside of the inner pipe and is spaced apart from the inner pipe. . The inner tube and the outer tube are spaced apart to form a certain annular space. Gas fuel leaks are detected while continuously ventilating the annular space. This double pipe structure allows immediate detection of damage to the inner pipe or gas or fuel leak, ensuring the safety of the vessel and crew.

When the gas fuel operation of the propulsion engine is stopped (gas stop), fuel change, the engine, etc. are not operated for a long time, or during internal maintenance, maintenance, equipment inspection, or shutdown of the engine or fuel supply section, fuel is not supplied to the engine. The fuel remaining in the equipment such as the supply pipes and engine is completely discharged. In this embodiment of the system, in this case, the gas fuel supply is blocked by the GVT (100) operating as a master valve, and the gas fuel remaining inside the double pipe (FLb) between the GVT and the propulsion engine among the fuel supply pipes is discharged to the vent line (VL). ) is discharged through.

The GVT (100) includes a first valve 110 disposed between the fuel supply unit and the connection portion of the vent line, a second valve 120 disposed between the connection portion and the propulsion engine, and a third valve 130 provided in the vent line. ), and includes a fourth valve 140 disposed in a venting pipe connected from the fuel supply pipe at the rear end of the second valve to the vent line at the rear end of the third valve.

Among them, the first valve 110 operates as a master gas valve to block the supply of gas fuel to the fuel supply pipe, and accordingly, in the system of this embodiment, it was previously placed in the cargo compressor room to block the supply of gas fuel. The master gas valve can be deleted.

GVT receives signals under the control of the propulsion engine's ECS (Engine control system) (not shown) and opens and closes each valve to control gas fuel supply to the engine. The ECS of the propulsion engine closes the GVT in the following situations.

-When pressing the gas stop button or fuel changeover on the engine's Main Operating Panel (MOP)

-If a gas leak is detected within the annular space

-Ventilation failure in the engine room or annular space

When it is necessary to block the supply of liquefied gas according to a signal from the ESD (Emergency Shutdown System) (not shown) or various causes, the master gas valve was conventionally turned on/off, but in the system of this embodiment, the GVT is operated as a master valve, Signals connected to the conventional master gas valve, including ESD, are connected to GVT.

IMO's IGC Code requires that the fuel supply pipe connected to the engine room (engine room) after the master gas valve be installed as a double wall pipe. In this embodiment, the fuel supply pipe is installed on the upper deck adjacent to the engine room and is separate from the cargo compressor room. By providing a separate GVT room (GR) and giving the master valve function to the GVT (100) installed in the GVT room, the double pipe only needs to be installed from the GVT room (GR) to the propulsion engine, thus reducing the installation length of the double pipe compared to before. It can be significantly reduced and installation costs can be reduced. In addition, the amount of remaining gas fuel inside the double pipe discharged through the vent line in the event of a gas stop or fuel change can be reduced, solving the problems of methane slip and greenhouse gas emissions when using gas fuel.

According to the results of a simulation by applying two ME-GI engines to the applicant's LNGC, according to the existing system, the length of the double pipe that must be discharged through the vent line is 140 m, and the amount of methane released into the atmosphere per stop of gas fuel operation is 140 m. However, when applying the system in this embodiment, the length of the double pipe is 40 m and the amount of methane released into the atmosphere per stop of gas fuel operation is 0.09 kg, which is expected to reduce the amount of methane released into the atmosphere by about 45% compared to the conventional system. It was predicted.

Meanwhile, an extraction fan 200 is provided to ventilate the GVT room, and an ventilation pipe (EL) is provided to exhaust air from the GVT room to overboard.

As in the first embodiment shown in FIG. 3, the ship is equipped with two propulsion engines (ME), and two GVTs (100) to control fuel supply to each of the two propulsion engines in one GVT room (GR). It can be configured to be placed.

As with the system of the second embodiment shown in FIG. 4, two propulsion engines (ME) are provided on a ship, and two GVT rooms (GRa, GRb) where GVTs are placed to control fuel supply to each of the two propulsion engines. It can also be provided on the port and starboard sides respectively.

As seen above, when applying the system of this embodiment, it is possible to significantly reduce the amount of gas fuel vented when gas operation is stopped by significantly shortening the length of the double pipe while meeting the safety regulations stipulated by the International Maritime Organization. It can reduce greenhouse gas emissions from operations and reduce installation costs.

It is obvious to those skilled in the art that the present invention is not limited to the above-mentioned embodiments, and that it can be implemented with various modifications or variations without departing from the technical gist of the present invention. It was done.

ME: propulsion engine
ER: Engine room
CCR: Cargo Compressor Room
GR: GVT room
100: GVT
200: Ventilator
300: Fuel supply unit
FLa, FLb: Fuel supply pipe
VL: vent line

Claims (9)

An engine room where the ship's propulsion engine supplied with liquefied gas as fuel is located;
A cargo compressor room provided on the upper deck and in which a fuel supply unit is arranged to supply liquefied gas according to the fuel supply conditions required by the propulsion engine;
A GVT room provided adjacent to the engine room at the upper part of the deck and where a GVT (Gas Valve Train) including a plurality of valves for controlling fuel supply from the fuel supply unit to the propulsion engine is disposed; and
Including a vent line connected from the GVT,
When the gas fuel operation of the propulsion engine is stopped (Gas Stop), the gas fuel supply is blocked by the GVT and the gas fuel remaining in the fuel supply pipe between the GVT and the propulsion engine is discharged to the vent line. Ship's liquefied gas fuel supply system. The method of claim 1, wherein the GVT is
a first valve disposed between the fuel supply part and the connection part of the vent line;
a second valve disposed between the connection portion and the propulsion engine; and
It includes a third valve provided in the vent line,
The first valve is a ship's liquefied gas fuel supply system, characterized in that it operates as a master gas valve to block the supply of gas fuel to the fuel supply pipe. The method of claim 2, wherein the GVT is
A liquefied gas fuel supply system for a ship further comprising a fourth valve disposed in a venting pipe connected from a fuel supply pipe at a rear end of the second valve to a vent line at a rear end of the third valve. According to clause 3,
The GVT room is provided as a separate space separated from the cargo compressor room between the cargo compressor room and the engine room,
A ship's liquefied gas fuel supply system, characterized in that the fuel supply pipe between the GVT room and the propulsion engine is provided as a double wall pipe. According to clause 4,
A liquefied gas fuel supply system for a ship further comprising an extraction fan provided for ventilation of the GVT room. According to clause 5,
The propulsion engine is a liquefied gas fuel supply system for a ship, characterized in that it is a dual fuel engine supplied as fuel by LNG and oil compressed to 10 to 350 bar. According to clause 1,
The GVT receives a control signal from the ship's ECS (Engine control system) to control the supply of gas fuel from the fuel supply unit to the propulsion engine, and receives a control signal from the ship's ESD (Emergency Shutdown System) to block the supply of gas fuel to the propulsion engine. A liquefied gas fuel supply system for ships, characterized in that: According to any one of claims 1 to 7,
The ship is equipped with two propulsion engines,
A ship's liquefied gas fuel supply system, characterized in that two GVTs are provided in the GVT room to control fuel supply to each of the two propulsion engines. According to any one of claims 1 to 7,
The ship is equipped with two propulsion engines,
A ship's liquefied gas fuel supply system characterized by two GVT rooms where GVTs are placed to control fuel supply to each of the two propulsion engines.

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