KR20160120047A - A vessel with a high-pressure injection engine in a hull - Google Patents

Abstract

Provided by the present invention is a vessel which has a high pressure gas injection engine in a hull. The vessel comprises: a storage tank (11) which stores liquefied gas; a compression means (13) which receives and compresses evaporation gas generated in the storage tank; a pressure control means (17) which supplies the evaporation gas compressed in the compression means to the high pressure gas injection engine as fuel by more pressurizing the evaporation gas at a pressure required in the pressure gas injection engine (21); a temperature control means (19) which heats fuel pressurized in the pressure control means at a temperature required in the high pressure gas injection engine; and a heat exchanger (15) which cools down evaporation gas which is not supplied to the high pressure gas injection engine in the evaporation gas compressed in the compression means by exchanging heat with evaporation gas discharged from the storage tank. The main ingredient of the liquefied gas is a material whose boiling point is equal to or higher than -110 C at atmospheric pressure such as ethane, ethylene, propane, butane, propylene, etc. The compression means is able to compress the liquefied gas at pressure equal to or higher than the critical pressure of a material which is the main ingredient of the liquefied gas.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a high-pressure gas injection engine,

The present invention relates to a ship equipped with a high-pressure gas injection engine in a hull.

In general, among the waste gases emitted from vessels, nitrogen oxides (NOx) and sulfur oxides (SOx) are regulated by the International Maritime Organization, and recently, the emission of carbon dioxide (CO ₂ ) is also regulated . Particularly, in the case of nitrogen oxide (NOx) and sulfur oxides (SOx), it was raised through the Protocol of the Maritime Pollution Prevention Convention (MARPOL) in 1997, In May, the requirements for the fermentation were satisfied and the regulations are being implemented.

Accordingly, various methods for reducing nitrogen oxide (NOx) emissions have been introduced in order to meet these requirements. As one of these methods, a high pressure gas which can use hydrocarbon such as natural gas, Injection engines have been developed and used.

Examples of the high-pressure gas injection engine include ME-GI engine and ME-LGI engine. The ME-GI engine is seen as an environmentally friendly next-generation engine that can reduce pollutant emissions by 23%, nitrogen compounds 80%, and sulfur compounds 95% or more, compared with diesel engines of the same class.

The ME-GI engine, when installed in the hull for propulsion of the ship, may be installed directly on propeller propellers. For this purpose, the ME-GI engine can be composed of a two-stroke engine rotating at low speed. That is, the ME-GI engine may be a low-speed two-stroke high-pressure gas injection engine.

Such an ME-GI engine may be installed in a vessel, such as a liquefied gas carrier, which stores and transports the liquefied gas in a cryogenic storage tank.

For example, an LNG carrier for transporting liquefied natural gas (LNG) will use natural gas as the fuel for the ME-GI engine, and depending on the load, will have an output of about 150-400 bara Pressure) high-pressure fuel gas supply pressure is required.

It is obtained by cooling liquefied gas such as LNG at a cryogenic temperature. It is very suitable for long distance transportation through the sea because its volume is reduced drastically compared to when it is in a gaseous state. The liquefied gas carrier, such as an LNG carrier, is used to load the liquefied gas with the liquefied gas and then to the sea to unload the liquefied gas to the onshore site. For this purpose, a storage tank capable of withstanding the extremely low temperature of the liquefied gas ).

Since the liquefaction temperature of natural gas is about -163 ° C at normal pressure, LNG has a temperature of -163 ° C at normal pressure. Lt; RTI ID = 0.0 > slightly < / RTI > In the case of LNG carrier, for example, LNG storage tank of LNG carrier is heat-treated, but external heat is continuously transmitted to LNG, so that LNG is stored in LNG tank during LNG transportation by LNG carrier. The boil-off gas (BOG) is generated in the LNG storage tank continuously in the tank. In liquefied gas storage tanks that store gaseous liquefied gas at room temperature and normal pressure even though liquefaction temperature is higher than that of LNG, evaporation gas is inevitably generated.

The generated evaporation gas increases the pressure in the storage tank and accelerates the flow of the liquefied gas in accordance with the shaking motion of the ship, which may cause a structural problem, so it is necessary to suppress the generation of the evaporation gas.

In order to suppress and treat the evaporation gas in the storage tank of the liquefied gas carrier, a method of discharging the evaporation gas to the outside of the storage tank and incinerating it, a method of discharging the evaporation gas to the outside of the storage tank, A method of returning to the storage tank again, a method of using evaporation gas as the fuel used in the propulsion engine of the ship, a method of suppressing the generation of evaporation gas by keeping the internal pressure of the storage tank high, alone or in combination Can be used.

In the case of a ship equipped with an evaporating gas remelting device, in order to maintain an appropriate pressure of the storage tank, the evaporation gas inside the storage tank is discharged outside the storage tank and is re-liquefied through the re-liquefaction device. At this time, the discharged evaporated gas may be re-liquefied through a heat exchange with a refrigerant cooled at a cryogenic temperature, for example, a nitrogen refrigerant, a mixed refrigerant, etc., in a liquefaction device including a refrigeration cycle, and then returned to the storage tank.

For example, in the case of an LNG carrier equipped with a DFDE propulsion system, the evaporating gas was treated at a proper pressure and temperature through a compressor and a heater, and then supplied to the DFDE as fuel, , When the amount of fuel required in the engine is less than the amount of evaporated gas generated, there is a problem that the evaporated gas must be burned in a gas combustion unit (GCU) or vented into the atmosphere.

For example, in the case of an LNG carrier equipped with a liquefaction plant and a low-speed diesel engine, although the BOG can be treated through a liquefaction plant, the complexity of operation of the liquefying apparatus using nitrogen refrigerant makes it possible to control the entire system There is a problem that a considerable amount of power is consumed in a complicated and liquefying facility.

As a result, it is necessary to continuously research and develop a system and a method for efficiently treating evaporative gas generated naturally from the storage tank storing the liquefied gas.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is an object of the present invention to provide a high pressure gas injection engine for a ship, which pressurizes evaporated gas discharged from a liquefied gas storage tank and cools it by cold heat of evaporation gas newly discharged from a storage tank, Pressure gas injection engine for use as a fuel of a high-pressure gas engine or returning to a storage tank so that evaporation gas can be efficiently used and treated.

According to an aspect of the present invention, there is provided a vessel equipped with a high-pressure gas injection engine in a hull, the vessel comprising: a storage tank storing liquefied gas; A compression means for receiving and compressing the evaporation gas generated in the storage tank; Pressure regulating means for further pressurizing the evaporated gas pressurized by the compressing means to a pressure required by the high-pressure gas-injection engine and supplying the pressurized gas as fuel to the high-pressure gas-injection engine; A temperature regulating means for heating the pressurized fuel in the pressure regulating means to a temperature required by the high-pressure gas injection engine; A heat exchanger for exchanging heat between the evaporation gas not supplied to the high pressure gas injection engine and the evaporation gas discharged from the storage tank among the evaporation gases compressed by the compression means; Wherein the liquefied gas is a hydrocarbon having a boiling point of at least -110 DEG C at normal pressure and is equipped with a high pressure gas injection engine in a hull.

The compression means can compress the liquefied gas to a pressure equal to or higher than the critical pressure.

The liquefied gas may be liquefied ethane gas or liquefied ethylene gas, and the compression means may compress the liquefied ethane gas or the liquefied ethylene gas to 50 to 100 bar.

The ship may further include decompression means for decompressing the evaporated gas cooled in the heat exchanger.

The vessel may further include a gas-liquid separator installed to return only the liquid component to the storage tank, among the evaporated gas that has been reduced in pressure while passing through the decompression means and brought into a gas-liquid mixed state.

Of the evaporated gas that has been reduced in pressure and passed through the decompression means and brought into a gas-liquid mixed state, the gaseous component can be merged into the evaporated gas discharged from the storage tank and supplied to the compression means.

Both the gas component and the liquid component can be returned to the storage tank in the evaporated gas that is reduced in pressure while passing through the decompression means and brought into the vapor-liquid mixed state.

The compression means may include a plurality of compressors for compressing the evaporated gas and a plurality of intercoolers for cooling the evaporated gas whose temperature has risen while being compressed in the compressor.

According to the present invention, the evaporation gas discharged from the liquefied gas storage tank is pressurized, cooled by the cold heat of the evaporated gas newly discharged from the storage tank, and then used as fuel for the ship's high-pressure gas injection engine or returned to the storage tank, A ship equipped with a high-pressure gas injection engine in the hull which can efficiently use and treat the evaporation gas can be provided.

Accordingly, according to the present invention, since all evaporative gas generated while being transported as cargo (i.e. liquefied gas) can be used as fuel for the engine or can be re-liquefied and returned to the storage tank and stored, it is consumed in the GCU It is possible to reduce the amount of the evaporated gas that is discarded, thereby increasing the cargo carrying amount.

According to the vessel of the present invention, it is possible to re-liquefy the evaporated gas generated in the storage tank without installing a re-liquefying apparatus that requires excessive energy consumption, thereby saving the energy consumed in the re-liquefying apparatus and the operation cost .

Further, according to the ship of the present invention, there is no need to provide a remanufacturing device (that is, a nitrogen refrigerant refrigeration cycle or a mixed refrigerant refrigeration cycle using a separate refrigerant) that requires a large initial installation cost, , It is not necessary to additionally provide a facility for supplying and storing the refrigerant, and the initial installation cost for constituting the entire system can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic configuration diagram showing an evaporative gas processing system of a ship equipped with a high-pressure gas injection engine in a hull according to a first embodiment of the present invention; Fig.
2 is a schematic configuration diagram showing an evaporative gas processing system of a ship equipped with a high-pressure gas injection engine in a hull according to a second embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the configuration and operation of an embodiment of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments may be modified into various other forms, and the scope of the present invention is not limited to the following embodiments.

The high-pressure gas injection engine mounted in the hull of a ship can use liquefied gas as fuel together with oil, such as ME-GI engine or ME-LGI. In the present specification, 'high pressure' should be understood to mean a pressure required for supplying fuel to a gas injection engine such as an ME-GI engine, for example, a pressure of about 150 to 400 bara (absolute pressure).

The liquefied gas supplied as fuel to the high-pressure gas injection engine can be stored in a storage tank installed inside or outside of the hull (for example, at the top of the deck), and this storage tank can accommodate liquefied gas as a cargo or fuel have. That is, the storage tank may be a cargo tank or a fuel tank. Storage tanks for receiving gaseous liquefied gas at normal temperature and normal pressure can be used, for example, in storage tanks developed to house LNG, i.e. membranous storage tanks (such as NO 96, Mark III to V tanks) or standalone storage tanks IMO type A, B, and C tanks). The storage tank may be an insulating tank or a pressurized tank.

According to one embodiment of the present invention, the liquefied gas contained in the storage tank is in a gaseous state at atmospheric pressure (approximately 1 atm) and at room temperature (approximately 25 ° C) and may have a higher boiling point than liquefied natural gas have. For example, the liquefied gas may be a hydrocarbon having a boiling point at normal pressure of about -110 DEG C or higher. More preferably, the liquefied gas may be a gaseous hydrocarbon component such as ethane, ethylene, propane, propylene, butane or the like at normal pressure and at a boiling point of at least about -110 DEG C at normal pressure. Further, according to one embodiment of the present invention, the liquefied gas contained in the storage tank can be used as fuel in a high-pressure gas injection engine mounted in the hull.

For example, according to one embodiment of the present invention, the liquefied gas contained in the storage tank may contain hydrocarbon components such as methane, ethane, propane, etc., alone or in combination, for example, It may be a hydrocarbon gas. Alternatively, according to one embodiment of the present invention, the liquefied gas contained in the storage tank may contain liquefied petrochemical gas such as ethylene, acetylene, propylene, liquefied carbon dioxide, liquefied ammonia, etc. singly or in combination, For example, the main component of each liquefied gas may be ethylene, acetylene, propylene, carbon dioxide, ammonia, and the like.

As a vessel equipped with a high-pressure gas injection engine in a hull according to an embodiment of the present invention, a storage tank for storing the above-described liquefied gas as a cargo is connected to a liquefied gas carrier (for example, a liquefied ethane gas carrier LEGC; Liquefied Ethane Gas Carrier).

Fig. 1 is a schematic structural view showing an evaporative gas processing system of a ship equipped with a high-pressure gas injection engine in a hull according to a first embodiment of the present invention.

1 shows an example in which the present invention is applied to a liquefied ethane gas carrier equipped with a high-pressure gas injection engine capable of using ethane gas as a fuel. However, the present invention is applicable to all types of gas- It can be applied to ships. In the present specification, the term 'ship' includes not only floating structures capable of propelling a magnetic force from a propulsion power from a high-pressure gas injection engine but also various marine plants used for mooring or fixed at one point in the sea for use in a specific use Should be considered.

In the present specification, 'liquefied ethane gas' does not mean that the liquefied gas is purely composed of 100% pure ethane but should be regarded as meaning liquefied gas whose main component is ethane. That is, the 'liquefied ethane gas' may contain a mixture of hydrocarbon components such as methane, propane, and butane and nitrogen.

Like the above-mentioned liquefied ethane gas, the term 'liquefied ethylene gas' in this specification does not mean that it is composed of only 100% pure ethylene component, and it should be considered that the main component means liquefied gas composed of ethylene. That is, the 'liquefied ethylene gas' may contain some components other than ethylene.

A ship equipped with a high-pressure gas injection engine in a hull according to a first embodiment of the present invention includes a storage tank 11 for storing a liquefied gas such as liquefied ethane gas or liquefied ethylene gas, Pressure gas injection engine 21 that can use the liquefied gas stored in the high-pressure gas injection engine 11 as fuel.

The storage tank can have a sealing and an insulating barrier to store liquefied gas such as liquefied ethane gas or liquefied ethylene gas at a low temperature state, but it can not completely block heat transmitted from the outside. Accordingly, in the storage tank 11, the evaporation of the liquefied gas is continuously performed. In order to maintain the internal pressure of the storage tank rising due to the generation of the evaporation gas at an appropriate level, 11) Exhaust the evaporated gas inside. Although not shown, a discharge pump may be installed inside the storage tank 11 to discharge the liquefied gas to the outside of the storage tank when necessary.

As the high-pressure gas injection engine, for example, ME-GI engine or ME-LGI engine can be used. The high-pressure gas injection engine can use liquefied gas stored in the storage tank 11 together with oil as fuel, and can use only oil as fuel or liquefied gas and oil as a fuel, if necessary. For example, in the case of ME-GI engine or ME-LGI engine, since oil is used for pilot ignition, liquefied gas alone can not operate. However, according to the present invention, It is possible.

The natural gas BOG generated and discharged from the storage tank 11 for storing the liquefied gas can be conveyed along the evaporation gas supply line L1 and compressed by the compression means 13. [ In the compression means 13, the evaporated gas can be compressed to a critical pressure of ethane of about 48 bar or more. For example, the evaporation gas may be compressed at a pressure of about 50 bara or more, preferably about 50 to 100 bara, for example, in the compression means 13, and then supplied as fuel to the high-pressure gas injection engine 21 . When the pressure of the ethane gas or the ethylene gas is less than 50 bara, the re-liquefaction efficiency at the time of heat exchange described later may be low, which is undesirable. Further, the higher the pressure of the ethane gas or the ethylene gas, the better the re-liquefaction efficiency. However, since the energy consumed by the compression means 13 increases, it is necessary to consider both the re-liquefaction efficiency and the energy consumed in compression.

The compression means 13 may comprise one or more compressors 13a for increasing the pressure of the evaporating gas and one or more intermediate coolers 13b for cooling the evaporating gas whose temperature has risen while being compressed. The compression means 13 may be configured to compress the evaporation gas at about -70 to -40 占 폚 and atmospheric pressure discharged from the storage tank 11 to approximately 30 to 50 占 폚 and 50 to 100 bara. Although the compression means 13 of multi-stage compression including three compressors 13a and three intermediate coolers 13b is illustrated in Fig. 1, the number of compressors and intercoolers can be changed as needed. Also, the compression means may be modified to have a structure in which a plurality of independent compressors are connected in series, in addition to a structure in which a plurality of compressors are arranged integrally in one body. The compressor 13a included in the compression means 13 may be a reciprocating or centrifugal compressor.

The evaporated gas compressed in the compression means 13 may be supplied as fuel to the high pressure gas injection engine 21, for example, the ME-GI engine, or returned to the storage tank 11. The evaporated gas returned to the storage tank 11 among the evaporated gases compressed by the compression means 13 is heat-exchanged in the heat exchanger 15 with the evaporated gas discharged from the storage tank 11 and conveyed to the compression means 13 It can be cooled to about -60 to -20 ° C, or about 60 to 100 bara. The cooled evaporated gas can be liquefied.

In the case of ethane, the critical pressure is about 48 bar, so that the evaporated gas (i.e., ethane gas) pressurized to about 50 to 100 bara while passing through the compression means 13 can be regarded as a supercritical state. Since the gas and liquid can not be distinguished in the supercritical state, the expression 'the evaporation gas is liquefied' lowers the temperature of the evaporation gas (or changes from a supercritical state with a low density to a supercritical state with a high density) Should be accepted as.

On the other hand, the supercritical state means that the supercritical state means that the state satisfies both the critical pressure condition and the critical temperature condition. According to the theory, the ethane gas pressurized at about 50 to 100 bara is compressed 13, and the phase change from the supercritical state to the liquid state (supercooled liquid state) can be seen as cooling in the heat exchanger 15.

As described above, in the heat exchanger 21, according to the theory that the refrigerant is supplied from the evaporative gas before the compressed evaporative gas is compressed (or supercritical state is satisfied because both pressure and temperature conditions are satisfied), the supercritical state In a supercooled liquid state).

It is possible to supply all of the compressed evaporated gas to the high pressure gas injection engine 21 through the fuel supply line L3 in accordance with the required amount of fuel required in the high pressure gas injection engine 21, And may be supplied to the high-pressure gas injection engine 21 through the fuel supply line L3.

That is, the evaporated gas pressurized by the compression means 13 while being transported along the evaporated gas discharge line L1 can be branched into the fuel supply line L3 and the evaporated gas recovery line L5. The fuel supply line L3 can be extended to supply the pressurized evaporation gas to the high-pressure gas injection engine 21, as described above. Then, the evaporation gas recovery line L5 can be extended to return the cooled evaporation gas to the storage tank 11.

For example, when the evaporation gas discharged from the storage tank 11 and compressed by the compression means 13 (that is, the entire evaporation gas discharged from the storage tank) is referred to as a first stream, the first stream of the evaporation gas is compressed The second stream is supplied as fuel to the high-pressure gas injection engine 21 via the fuel supply line L3 and the third stream is supplied to the high-pressure gas injection engine 21 via the evaporation gas recovery line L5 To return to the tank (11).

To regulate the pressure and temperature of the fuel supplied to the high pressure gas injection engine 21 (i.e., the second stream of compressed and cooled evaporation gas) to the pressure and temperature required by the high pressure gas injection engine, L3 may be provided with pressure regulating means 17 such as a pump and temperature regulating means 19 such as a heater and a vaporizer.

The pressure regulating means 17 can further compress the fuel compressed at approximately 50 to 100 bara in the compression means 13 to a high pressure of approximately 150 to 400 bara.

The pressure regulating means 17 can be configured to regulate the pressure of the fuel according to the load of the high-pressure gas injection engine 21. [ Alternatively, the pressure regulating means 17 may constitute the entire system so as to pressurize the fuel at a constant pressure and regulate the pressure of the fuel immediately before being supplied to the high-pressure gas injection engine 21 by a pressure regulating valve (not shown) have.

Although not shown, a recirculation line may be provided around the pressure regulating means 17. The recirculation line is provided so as to be able to return the pressurized fuel to the upstream side of the pressure regulating means (17) while passing through the pressure regulating means (17), and may include a valve for opening and closing the flow path. When the recirculation line is installed, when the amount of fuel required by the high-pressure gas injection engine 21 suddenly decreases (for example, when the speed of the ship is reduced or when the ship is stopped), surplus fuel, Can be recirculated to the upstream side of the pressure regulating means (17) without being supplied to the injection engine (21). That is, even if the pressure regulating means 17 does not respond quickly to the fuel demand change by inertia, it can be supplemented by the recirculation line.

The fuel pressurized from the pressure regulating means 17 to the required pressure of the high pressure gas injection engine 21 is regulated to the required temperature of the high pressure gas injection engine 21 in the temperature regulating means 19 and then supplied to the high pressure gas injection engine 21, . The temperature regulating means 19 can regulate the temperature of the pressurized fuel to about 40 to 50 DEG C required by the engine. Since the fuel pressurized by the high-pressure gas injection engine 21, that is, ethane is in a supercritical state, the high-pressure compressed ethane is neither gas nor liquid.

On the other hand, the evaporation gas (that is, the third stream of the evaporation gas) returned to the storage tank 11 among the evaporation gases compressed by the compression means 13 is discharged from the storage tank 11 and conveyed to the compression means 13 (Liquefied) at about -60 to -20 占 폚 and about 60 to 100 bara by heat exchange in the heat exchanger 15 with the evaporating gas (i.e., the first stream of the evaporating gas).

According to the present embodiment, since only the evaporated gas not used as fuel among the evaporated gases pressurized by the compression means 13 is supplied to the heat exchanger 15 and cooled, the cooling of the pressurized evaporated gas can be performed more efficiently have.

Liquefied BOG (LBOG) cooled in the heat exchanger 15 is reduced to a pressure equal to or slightly higher than the internal pressure of the storage tank 11 before returning to the storage tank 11. To this end, the evaporation gas recovery line L5 may be provided with decompression means 23. As the decompression means 23, for example, an expansion valve or an expander, such as a J-T valve, may be used.

The third stream of the evaporated gas LBOG cooled in the heat exchanger 15 may be supplied to the gas-liquid separator 25 in a vapor-liquid mixed state after being reduced in pressure (that is, expanded) while passing through the decompression means 23. The LBOG can be decompressed (for example, reduced to -1 to 2 bar and -110 to -80 캜) at approximately normal pressure while passing through the decompression means 23. The third stream of the decompressed evaporated gas is separated from the gas and liquid components in the gas-liquid separator 25 and the liquid component, that is, the liquefied ethane gas (LEG), is transferred to the storage tank 11 through the evaporated gas recovery line L5 And the gas component (approximately -110 to -80 ° C), that is, the evaporation gas can be joined to the evaporation gas which is discharged from the storage tank 11 through the evaporation gas circulation line L7 and supplied to the compression means 13 . The evaporation gas circulation line L7 may extend from the upper end of the gas-liquid separator 25 and be connected upstream of the heat exchanger 15 in the evaporation gas discharge line L1.

2 is a schematic structural view showing an evaporative gas processing system of a ship equipped with a high-pressure gas injection engine in a hull according to a second embodiment of the present invention.

A ship equipped with a high-pressure gas injection engine in a hull according to a second embodiment of the present invention includes a storage tank 11 for storing a liquefied gas such as liquefied ethane gas or liquefied ethylene gas, Pressure gas injection engine 21 that can use the liquefied gas stored in the internal combustion engine 11 as a fuel and the compression means 13 and the heat exchanger 15 for compressing the natural gas BOG And the like are the same as the first embodiment described above.

The system according to the second embodiment differs from the first embodiment in that both the liquid component and the gas component separated in the gas-liquid separator 25 are supplied to the storage tank 11, The difference from the embodiment is mainly described. In the system of the second embodiment shown in Fig. 2, the same constituent elements as those of the first embodiment are given the same reference numerals, and a detailed description thereof will be omitted.

1, the liquid component separated in the gas-liquid separator 25, that is, the liquefied ethane gas (LEG) is transferred to the storage tank 11 through the evaporative gas recovery line L5, and the gas component (approximately -110 to -80 ), That is, the evaporation gas is shown to be merged into the evaporation gas which is discharged from the storage tank 11 through the evaporation gas circulation line L7 and supplied to the compression means 13. However, according to the second embodiment, it is possible to supply both the liquid component and the gas component separated by the gas-liquid separator 25 to the storage tank 11. The gas component (approximately -110 to -80 ° C) separated in the gas-liquid separator 25 can be transferred to the storage tank 11 through the gas component recovery line L9.

Here, the gas component supplied to the storage tank 11 can be discharged from the storage tank through the evaporation gas discharge line L1 together with the newly generated evaporation gas in the storage tank 11. [

On the other hand, when it is expected that the amount of evaporative gas generated in the storage tank 11 is larger than the amount of fuel required in the high-pressure gas injection engine 21 and a surplus of evaporative gas is expected to be generated, So that the system can be configured to be used in the evaporation gas consumption means. As the evaporation gas consumption means, a DF engine, a GCU, a gas turbine, a boiler, etc., which can be used as a fuel by mixing liquefied gas alone or with oil, may be used.

According to one embodiment of the present invention, for example, evaporative gas generated during transportation of a cargo (i.e., LEG) of a liquefied ethane gas carrier can be used as fuel for the engine or re-liquefied and returned to the storage tank for storage It is possible to reduce or eliminate the amount of evaporated gas consumed in GCU or the like and to re-liquefy and treat the evaporated gas without the need to provide a re-liquefying device using a separate refrigerant such as nitrogen.

Further, since there is no need to provide a re-liquefying apparatus using a separate refrigerant (i.e., a nitrogen refrigerant refrigeration cycle or a mixed refrigerant refrigeration cycle), there is no need to additionally provide a facility for supplying and storing the refrigerant, It is possible to reduce the initial installation cost and the operating cost for constructing the system.

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 and scope of the invention will be.

11: storage tank 13: compression means
13a: Compressor 13b: Intermediate cooler
15: heat exchanger 17: pressure regulating means
19: Temperature control means 21: High pressure gas injection engine
23: decompression means 25: gas-liquid separator
L1: Evaporative gas discharge line L3: Fuel supply line
L5: Evaporative gas recovery line L7: Evaporative gas circulation line
L9: Gas component recovery line

Claims (8)

As a ship equipped with a high-pressure gas injection engine in the hull,
A storage tank for storing the liquefied gas;
A compression means for receiving and compressing the evaporation gas generated in the storage tank;
Pressure regulating means for further pressurizing the evaporated gas pressurized by the compressing means to a pressure required by the high-pressure gas-injection engine and supplying the pressurized gas as fuel to the high-pressure gas-injection engine;
A temperature regulating means for heating the pressurized fuel in the pressure regulating means to a temperature required by the high-pressure gas injection engine;
A heat exchanger for exchanging heat between the evaporation gas not supplied to the high pressure gas injection engine and the evaporation gas discharged from the storage tank among the evaporation gases compressed by the compression means;
/ RTI >
Wherein the liquefied gas is a hydrocarbon having a boiling point of -110 DEG C or higher at normal pressure, and a vessel equipped with a high-pressure gas injection engine in the hull. The method according to claim 1,
Wherein the compression means compresses the liquefied gas to a critical pressure or more, and a high pressure gas injection engine is mounted in the hull. The method according to claim 1,
The liquefied liquefied ethane gas or the liquefied ethylene gas,
Wherein the compression means compresses the liquefied ethane gas or the liquefied ethylene gas to 50 to 100 bar, wherein the high pressure gas injection engine is mounted in the hull. The method according to claim 1,
Further comprising a decompression means for decompressing the evaporated gas cooled in the heat exchanger, wherein the high pressure gas injection engine is mounted in the hull. The method of claim 4,
Further comprising a gas-liquid separator installed in the hull to return only the liquid component to the storage tank, among the evaporated gas that has been reduced in pressure while passing through the decompression means and brought into a gas-liquid mixed state. The method of claim 4,
Pressure gas injection engine is mounted in the hull, wherein the gas component is merged with the evaporation gas discharged from the storage tank and supplied to the compression means. The method of claim 4,
Pressure gas injection engine is mounted in a hull in which both the gas component and the liquid component are returned to the storage tank. The method according to claim 1,
Wherein the compression means includes a plurality of compressors for compressing the evaporation gas and a plurality of intermediate coolers for cooling the evaporation gas whose temperature has been increased while being compressed by the compressor.

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