KR20200087441A - Re-gasifying System And Method For Regasification Ship - Google Patents

Abstract

Disclosed are a regasification system of a regasification ship and a method thereof. The regasification system of a regasification ship of the present invention comprises: a storage tank provided on a regasification ship, and storing liquefied gas; a regasification unit for receiving the liquefied gas from the storage tank, and generating regasification gas to be transported outboard; a regasification boiler for producing steam to be supplied as a heat source for regasifying the liquefied gas to the regasification unit; and an oil burner for receiving oil as fuel, and producing steam to supply the same to the regasification unit. The regasification boiler receives and burns boil-off gas generated from the liquefied gas as fuel to produce steam, and is provided with one set thereof. The oil burner is provided with a smaller capacity than that of the regasification boiler, and steam is produced by the oil burner to be supplied to the regasification unit when steam cannot be produced by the boiler including a case that abnormality in a device of the boiler and abnormality in the supply of the boil-off gas to the boiler occur.

Description

Re-gasifying system and method for regasification ship

The present invention relates to a regasification system and method of a regasification vessel, and more specifically, to produce steam by supplying boiled gas generated from liquefied gas stored in a storage tank in a regasification vessel as fuel for a boiler, and producing it in a boiler When liquefied gas is regasified as a heat source and transferred to the outboard, but an oil burner with a smaller capacity than a boiler is provided, and steam cannot be produced by the boiler, including an abnormality in the equipment of the boiler and an abnormal supply of evaporated gas to the boiler. The present invention relates to a regasification system and method for a regasification vessel that produces steam with an oil burner and supplies it to a regasification unit.

The consumption of liquefied gas such as LNG (Liquefied Natural Gas) or LPG (Liquefied Petroleum Gas) is increasing worldwide. The liquefied gas is transported in a gaseous state through an on-shore or offshore gas pipeline, or is transported to a long-distance consumer while being stored in a liquefied gas carrier in a liquefied state. Liquefied gas such as LNG or LPG is obtained by cooling natural gas or petroleum gas to cryogenic temperature (about -163°C in the case of LNG), and its volume is significantly reduced compared to that in the gas state, making it suitable for long-distance transportation through sea.

Ships using LNG are typically LPG carriers, LNG carriers, liquid hydrogen carriers, and LNG self-propelled vessels such as RV (Regasification Vessel), LNG Floating Production Storage Offloading (FPSO), LNG FSRU Examples include offshore structures that do not have propulsion capabilities, such as (Floating, Storage, Regasification Unit), but are floating on the sea.

Among the vessels in which LNG is used, LNG regasification vessels are vessels or floating structures that have the function of storing cryogenic liquid LNG, and regasifying them to supply them to demand on land. Storage of LNG while floating in the sea This includes LNG FSRUs in the form of offshore floating structures with the purpose of regasification, and LNG RVs in the form of ships with self-propelling capabilities with the purpose of regasification while functioning as LNG carriers.

Such an LNG regasification vessel can regasify LNG as a heat source using seawater or air, which can be easily obtained at sea, and supply it to an on-site gas demand source.

In an LNG regasification vessel, BOG naturally occurring in an LNG storage tank may be compressed, or compressed by high pressure by pumping LNG, and then regasified to be transported out of the ship.

To this end, the vessel is supplied with a recondenser that compresses BOG generated in the LNG storage tank and mixes it with the LNG pumped in the LNG storage tank, an HP pump that receives compressed LNG from the recondenser, and compresses it at high pressure, compressed by the HP pump A vaporizer for vaporizing LNG supplied, a metering unit for transferring gas vaporized from the vaporizer to the outside of the vessel, a heat exchanger, a manifold, and the like may be configured.

In order to regasify low-temperature LNG, a lot of heat energy is required. When supplying a heat source from seawater that is easy to obtain from a ship, a large amount of seawater is required. As it can adversely affect marine ecosystems and destroy marine ecosystems, each country regulates them.

According to an aspect of the present invention for solving the above problems, a storage tank provided in a regasification vessel and storing liquefied gas;

A regasification unit receiving liquefied gas from the storage tank and generating a regasification gas to be transported out of the ship;

A regasification boiler for producing steam to be supplied as a heat source for regasifying the liquefied gas to the regasification unit; And

It includes an oil burner that is supplied with oil as fuel and produces steam to supply to the regasification unit.

The regasification boiler is supplied with fuel from the liquefied gas and burned to produce steam to produce steam, but one set is provided, and the oil burner is provided with a smaller capacity than the regasification boiler, and the device of the boiler is abnormal And when the steam cannot be produced by the boiler, including the supply of the boil-off gas to the boiler, the steam is produced by the oil burner and supplied to the regasification unit. .

Preferably, the regasification unit includes a high pressure pump that receives and compresses the liquefied gas; A vaporizer that receives the liquefied gas compressed by the high-pressure pump and revaporizes it by heat exchange with a heating medium; And a trim heater that receives the regasified gas from the vaporizer and further heats it.

Preferably, the regasification unit, a heat medium circulation line through which the heat medium to be exchanged in the vaporizer circulates; A heat medium pump provided on the heat medium circulation line to pump the heat medium; And a heating medium heater provided at a rear end of the heating medium pump.

Preferably, the steam produced in the regasification boiler is supplied as a heat source to at least one of the trim heater and the heat medium heater, and the trim heater and the heat medium heater are at least one of steam and seawater produced in the regasification boiler. It can be operated by being supplied as a heat source.

Preferably, a first oil fuel supply unit for supplying oil to the regasification boiler; A compressor that receives and compresses the boil-off gas generated in the storage tank; And a boiler fuel heater that receives the compressed boil-off gas from the compressor and heats it to supply it to the regasification boiler. Further comprising, the regasification boiler may be provided with a dual fuel (Dual Fuel) type that can receive the evaporation gas and oil as fuel.

Preferably, a feed pump provided in the storage tank to pump and transport the liquefied gas; A re-condenser that cools the boil-off gas compressed by the compressor with the liquefied gas transferred by the feed pump; A metering unit for measuring the flow rate of the regasification gas that is re-gassed after the regasification through the regasification unit; And a manifold provided downstream of the metering unit and connected to a pipe for transporting the regasification gas to the outboard. The liquefied gas condensed in the recondenser may be supplied to the high pressure pump.

Preferably, the engine that receives the compressed boil-off gas from the compressor to produce the electric power; An engine fuel heater that receives the compressed boil-off gas from the compressor and heats it according to the fuel supply condition of the engine to supply it to the engine; And a second oil fuel supply unit supplying oil to the engine. Further comprising, the engine may be provided with a dual fuel (Dual Fuel) type that can receive the evaporation gas and oil as fuel.

According to another aspect of the present invention, the liquefied gas stored in the storage tank in the regasification vessel is re-evaporated and transferred out of the ship,

Boil-off gas generated from the liquefied gas is supplied as fuel to the boiler to produce steam, and the liquefied gas is re-evaporated using the steam produced in the boiler as a heat source.

When only one set of the boiler is provided and an oil burner having a capacity smaller than that of the boiler is provided, when the steam cannot be produced by the boiler, including an abnormality in the device of the boiler and an abnormal supply of the evaporated gas to the boiler, the boiler A method for regasification of a regasification vessel is provided, characterized in that steam is produced by an oil burner and supplied to the regasification unit.

In the present invention, steam is produced by supplying boil-off gas to a boiler in a regasification vessel, and steam is used as a heat source for regasification of liquefied gas, thereby reducing the use of seawater used in the regasification vessel and discharging supercooled low temperature seawater. It can reduce the impact of marine ecosystems around ships and meet the environmental regulation standards of regasification vessel installation areas.

In addition, since the temperature of the heat medium can be operated higher than when using sea water as a heat source, the size of equipment such as a carburetor can be reduced, and the regasification system can be effectively operated even in regions where the temperature of sea water is low in polar regions or cold regions.

Furthermore, it is possible to reduce the operating cost by reducing the use of pumps for seawater intake, and to control the pressure of the storage tank by increasing the amount of evaporated gas consumed as fuel.

In addition, while supplying steam as a heat source for regasification through a regasification boiler, an oil burner having a capacity smaller than that of the regasification boiler is provided, and thus, the boiler is abnormal due to the abnormality of the device of the boiler, the supply of fuel such as evaporated gas, and the maintenance of the device. It is possible to keep the system operating by an oil burner when the furnace steam cannot be produced, thereby reducing installation and operation costs and contributing to securing space on board.

1 schematically shows a regasification system of a regasification vessel according to a basic embodiment of the invention.
2 schematically shows a regasification system of a regasification vessel according to a first embodiment of the present invention.
3 schematically shows an example of a regasification boiler structure that can be applied to embodiments of the present invention.

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

Hereinafter, the configuration and operation of the preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. Here, when adding reference numerals to the components of each drawing, it should be noted that the same components are denoted by the same reference numerals as much as possible even though they are displayed on different drawings.

1 schematically shows a regasification system of a regasification vessel according to a basic embodiment of the present invention, and FIG. 2 schematically shows a regasification system of a regasification vessel according to a first embodiment of the present invention, and FIG. An example of a regasification boiler configured in a seawater discharge system of a regasification vessel according to embodiments is schematically illustrated.

Liquefied gas in the present embodiments can be transported by being liquefied at a low temperature, and can be applied to all types of liquefied gas that can be transported by being regasified by being supplied as fuel such as an engine, evaporating gas is generated in a stored state. . Such liquefied gas is liquefied petrochemical such as Liquefied Natural Gas (LNG), Liquefied Ethane Gas (LEG), Liquefied Petroleum Gas (LPG), Liquefied Ethylene Gas, Liquefied Propylene Gas, etc. It can be gas. However, in the embodiments described below, LNG, which is a representative liquefied gas, is described as an example.

In addition, in the embodiments described below, the regasification vessel is a vessel or floating structure having a function capable of storing LNG in a cryogenic liquid state and regasifying it to supply it to offshore, such as a demand on land, for example, FSRU and This includes LNG RV.

1 and 2, the regasification system of a regasification vessel according to embodiments of the present invention is provided in a regasification vessel and receives a liquefied gas from a storage tank and a storage tank for storing liquefied gas It comprises a regasification unit for generating a regasification gas to be transported out of the ship, and a regasification boiler for producing steam to be supplied as a heat source for regasifying the liquefied gas to the regasification unit.

In this embodiment, the regasification boiler is characterized by supplying boiled gas generated from liquefied gas as fuel to produce and supply steam to a regasification unit, and the basic embodiment shown in FIG. 1 is two sets of regeneration 2, the first embodiment shown in FIG. 2 is provided with a set of regasification boilers 200 and an oil burner 270.

The regasification unit 100 is supplied with a liquefied gas and compressed by a high pressure pump 110, a compressed gas liquefied by a high pressure pump, and a vaporizer 120 for regasification by heat exchange with a heat medium, and a regasified gas regasified from a vaporizer It may include a trim heater 150 to receive additional heating. The high pressure pump may be supplied with a liquefied gas and compressed to a pressure required by an offshore consumer, for example, 50 to 100 barg, to be supplied to the vaporizer.

In this embodiment, the vaporizer 120 of the regasification unit is a device for regasifying liquefied gas in an indirect manner, and reheats the liquefied gas through heat exchange with liquefied gas while the heat medium circulates along the heat medium circulation line. To this end, one or more heat medium pumps 130 for pumping heat medium and a heat medium heater 140 at the rear end of the heat medium pump are provided in the heat medium circulation line GL of the regasification unit. The heat medium that circulates the heat medium circulation line may be, for example, glycol water, and a buffer tank (not shown) may be further provided in the heat medium circulation line to accommodate a volume change due to expansion and contraction of the heat medium.

Steam produced by the regasification boiler 200 may be supplied as a heat source to at least one of the trim heater 150 and the heat medium heater 140 of the regasification unit. Steam produced in a regasification boiler can be supplied to both the heat medium heater and the trim heater as a heat source, and as shown in FIGS. 1 and 2, heat is supplied to the heat medium heater 140 and the trim heater 150 as a heat source. It is also possible to provide a seawater heater 160 for heating the heat medium first by seawater upstream of the heater and to supply seawater as a heat source to the seawater heater and the trim heater. As such, each heater may be supplied with steam or seawater as a heat source, or may be supplied with both steam and seawater as a heat source. The seawater heater and the steam heater may be configured separately, but may be integrally manufactured.

If seawater discharge temperature is specified as a specific temperature, use the seawater as a heat source only up to the limit temperature, steam can be used as the heat source for the rest of the regasification, and when the seawater temperature is high, the load of the steam heater is variably operated. While regasifying to a certain level with a steam heater, the seawater can be configured to use the heat of the seawater from the trim heater to a limited temperature as a heat source. In areas where there is no limit on the temperature of seawater discharge, only seawater can be operated to supply the heater as a heat source for regasification.

As such, the trim heater and the heating medium heater may be operated by receiving steam and seawater produced by a regasification boiler (or oil burner) as a heat source, and may be configured in various combinations in addition to the systems illustrated in FIGS. 1 and 2. Through this, the temperature of the heat medium can be higher than when using sea water as a heat source, so the size of the vaporizer can be reduced, the temperature limit of sea water discharge is observed, and disturbance and destruction of the marine ecosystem caused by low temperature sea water discharge can be prevented.

In addition, unlike the above-described embodiments, the liquefied gas may be configured as a direct method of re-evaporating by directly exchanging heat with steam, air, and sea water (not shown). In this case, the regasification unit is supplied with liquefied gas and compressed. It may include a high pressure pump and a steam heater that receives the liquefied gas compressed by the high pressure pump and generates regasification gas by using the steam produced in the regasification boiler as a direct heat source.

In these embodiments, the regasification boiler is provided with a dual fuel type capable of receiving evaporation gas and oil as fuel, and a first oil fuel supply unit (FOS1) for supplying oil to the regasification boiler is provided. Can be. The regasification boiler operates to generate steam from the evaporation gas generated from the storage tank as fuel, and the first oil fuel supply unit may be provided for commissioning.

The basic embodiment shown in FIG. 1 is provided with two sets of regasification boilers 200, and the first embodiment shown in FIG. 2 is provided with only one set of regasification boilers 200, instead of a regasification boiler. A small capacity oil burner 270 is provided. It is configured to produce steam with an oil burner and supply it to the regasification unit when it is not possible to produce steam with the regasification boiler due to the abnormality of the device of the regasification boiler, the abnormal supply of boil-off gas to the boiler, and maintenance. Although it may be more effective to produce and supply steam through a regasification boiler, it is quite expensive to build two sets of regasification boiler systems, and the installation space is also large, so the first embodiment solves this problem. Only one set of regasification boilers is installed, and an oil burner with a smaller capacity is installed than the regasification boilers. Through this, it is possible to reduce installation and operation costs and contribute to securing space on board.

The oil burner is, for example, by mounting a fuel oil nozzle on a gas burner and applying a fuel oil supply system, or by preparing the burner itself as a DF burner capable of dual fuel combustion and applying a fuel oil supply system. It may be provided. In addition, the fuel oil supply system for supplying oil to the oil burner may additionally provide a separate system, and is connected to a first oil fuel supply unit (FOS1) provided to supply oil to a regasification boiler to supply oil to the oil burner. It can also be designed to supply.

3 schematically shows the structure of an example regasification boiler applied to the present embodiments. Combustion of fuel in the regasification boiler takes place inside the furnace 220, and the combustion air supplied from the forced draft fan is supplied by the burner 210 to the furnace, and the fuel supplied from the furnace Combust gas.

A water drum 230 is provided at the bottom of the regasification boiler, and a steam drum 260 is provided at the top, and the upper and lower drums are a tube 240 inside the boiler and an exterior. It is connected by Down Comer (250). The water supplied through the water drum moves to the upper steam drum along the tube inside the boiler while receiving heat from the combustion exhaust gas, and only the steam is separated from the steam drum and supplied to the outside. The remaining saturated water that is not evaporated from the steam drum increases in density as the temperature decreases and moves to the lower water drum through a down comer installed outside.

The regasification boiler may be installed in the engine room, may be installed separately in the stern engine casing & funnel, or may be installed in the regas area distant from the cabin for safety in the regasification vessel. have.

Meanwhile, a plurality of dual fuel type engines (Ea, Eb, Ec, and Ed) may be provided to receive the compressed boil-off gas from a compressor and produce electric power required for onboard or offboard. The engine may be, for example, DFDE (Dual Fuel Diesel Electric Engine) or DFDG (Dual Fuel Diesel Generator Engine).

In the system of the present exemplary embodiment, the evaporation gas generated from the storage tank is supplied and compressed by the fuel supply pressure of the engine and the regasification boiler, and the compressed evaporation gas is supplied from the compressor to evaporate according to the fuel supply conditions of the engine. The engine fuel heater 450 for heating the gas and supplying it to the engine, and the boiler fuel heater 400 for receiving the compressed evaporation gas from the compressor and heating it to supply it to the regasification boiler are connected from the storage tank to the regasification boiler and the engine. It may be provided in the fuel supply line (FL).

A second to fifth oil fuel supply unit (FOS2 to FOS5) for supplying oil to each of the dual fuel engines may be further included, and the first oil fuel supply unit for supplying oil to the regasification boiler and the oil supply to the engine All of the second to fifth oil fuel supply units may be configured independently.

The storage tank T is provided with a feed pump FP for pumping and transporting liquefied gas, and the liquefied gas transferred through the feed pump is introduced into the recondenser 500. A cargo pump (CP1) for pumping liquefied gas is also provided in the storage tank, and when the device of the feed pump is abnormal, the liquefied gas may be transferred by the cargo pump and supplied to the front of the recondenser and the high pressure pump.

In the re-condenser 500, the evaporated gas compressed by the compressor is cooled with liquefied gas transferred by the feed pump. The liquefied gas cooled and condensed in the re-condenser can be re-stored to a storage tank or supplied to a high-pressure pump and re-evaporated before being transported off-board.

After regasification through the regasification unit, the flow rate of the regasification gas that is transported out of the ship is measured by the metering unit 600, and a pipe for transferring the gas of regasification out of the manifold 700 is connected, so that the regasification gas is transported out of the ship. .

As described above, in the present embodiments, the use of seawater used in the regasification vessel by supplying the boil-off gas to the boiler in the regasification vessel to produce steam, and supplying steam as a heat source for regasification of the liquefied gas By reducing the capacity and use of pumps for seawater intake, it is possible to reduce the cost for device configuration and operation. In addition, it is possible to reduce environmental pollution caused by outboard discharge of supercooled seawater and adverse effects on marine ecosystems around the vessel.

Compared to when using seawater as a heat source, the temperature of the heating medium can be operated higher by steam, thereby reducing the size of the carburetor to realize a compact system, and effectively producing regasification gas even in areas with low seawater temperatures in polar or cold regions. Can supply.

The present invention is not limited to the above embodiments, and can be variously modified or modified within a range not departing from the technical gist of the present invention, which is obvious to those skilled in the art to which the present invention pertains. It is done.

T: Storage tank
CP: cargo pump
FP: feed pump
SP: Seawater supply pump
FL: fuel supply line
RL: Gas regasification line
GL: Heat medium circulation line
Ea, Eb, Ec, Ed: engine
FOS1 ~ FOS5: 1st to 5th oil fuel supply unit
100: regasification unit
110: high pressure pump
120: carburetor
130: heat medium pump
140: heating medium heater
150: trim heater
160: seawater heater
200: regasification boiler
270: oil burner
300: compressor
400: boiler fuel heater
450: engine fuel heater
500: recondenser
600: metering unit
700: Manifold

Claims (8)

A storage tank provided on the regasification vessel and storing liquefied gas;
A regasification unit receiving liquefied gas from the storage tank and generating a regasification gas to be transported out of the ship;
A regasification boiler for producing steam to be supplied as a heat source for regasifying the liquefied gas to the regasification unit; And
It includes an oil burner that is supplied with oil as fuel and produces steam to supply to the regasification unit.
The regasification boiler is supplied with fuel from the liquefied gas and burned to produce steam to produce steam, but one set is provided, and the oil burner is provided with a smaller capacity than the regasification boiler, and the device of the boiler is abnormal And when the steam cannot be produced by the boiler, including the supply of the boil-off gas to the boiler, the steam is produced by the oil burner and supplied to the regasification unit. According to claim 1, The regasification unit
A high pressure pump that receives and compresses the liquefied gas;
A vaporizer that receives the liquefied gas compressed by the high pressure pump and revaporizes it by heat exchange with a heating medium; And
A reheating system of a regasification vessel, including; a trim heater that receives the regasified gas from the vaporizer and further heats it. According to claim 2, The regasification unit
A heat medium circulation line through which the heat medium to be exchanged in the vaporizer circulates;
A heat medium pump provided on the heat medium circulation line to pump the heat medium; And
A regasification system of a regasification vessel further comprising a heat medium heater provided at a rear end of the heat medium pump. According to claim 3,
Steam produced in the regasification boiler is supplied as a heat source to at least one of the trim heater and the heat medium heater,
The trim heater and the heat medium heater are regasification systems of a regasification vessel, characterized in that the steam and seawater produced by the regasification boiler are operated by being supplied as a heat source. According to claim 2,
A first oil fuel supply unit supplying oil to the regasification boiler;
A compressor that receives and compresses the boil-off gas generated in the storage tank; And
A boiler fuel heater which receives the compressed boil-off gas from the compressor and heats it to supply it to the regasification boiler; Further comprising,
The regasification boiler is a regasification system of a regasification vessel, characterized in that it is provided with a dual fuel (Dual Fuel) type capable of receiving the evaporation gas and oil as fuel. The method of claim 5,
A feed pump provided in the storage tank to pump and transport the liquefied gas;
A re-condenser that cools the boil-off gas compressed by the compressor with the liquefied gas transferred by the feed pump;
A metering unit for measuring the flow rate of the regasification gas that is re-gassed after the regasification through the regasification unit; And
A manifold provided downstream of the metering unit and connected to a pipe for transporting the regasification gas outboard, further comprising,
The regasification system of a regasification vessel, characterized in that the liquefied gas condensed in the recondenser can be supplied to the high pressure pump. The method of claim 6,
An engine that receives the compressed boil-off gas from the compressor and produces the electric power;
An engine fuel heater that receives the compressed boil-off gas from the compressor and heats it according to the fuel supply condition of the engine to supply it to the engine; And
A second oil fuel supply unit supplying oil to the engine; Further comprising,
The engine is a regasification system of a regasification vessel, characterized in that it is provided with a dual fuel (Dual Fuel) type capable of receiving the evaporation gas and oil as fuel. In the regasification vessel, the liquefied gas stored in the storage tank is regasified and transferred to the outboard.
Boil-off gas generated from the liquefied gas is supplied as fuel to the boiler to produce steam, and the liquefied gas is re-evaporated using the steam produced in the boiler as a heat source.
When only one set of the boiler is provided and an oil burner having a capacity smaller than that of the boiler is provided, when the steam cannot be produced by the boiler, including an abnormality of the apparatus of the boiler and the supply of the evaporated gas to the boiler, the boiler A method of regasification of a regasification vessel, characterized in that steam is produced by an oil burner and supplied to the regasification unit.

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