KR101937508B1 - A Treatment System Of Liquefied Gas - Google Patents

Abstract

The present invention relates to a liquefied gas processing system, and more particularly, to a liquefied gas processing system comprising: an evaporation gas supply line connecting a high-pressure consumer to a liquefied gas storage tank to supply an evaporation gas; An evaporative gas compressor provided on the evaporative gas supply line for multi-stepping the evaporative gas; An evaporation gas branch line for supplying an evaporation gas pressurized by at least a part of the evaporation gas compressor to a low pressure consumer site; A liquefied gas supply line connecting the high-pressure consumer to the liquefied gas storage tank to supply liquefied gas; And an oil supply line connecting the high-pressure consumer at an oil storage tank. In the first mode, the evaporation gas of the liquefied gas storage tank is supplied to the low-pressure consumer, and in the second mode, And supplies the evaporated gas of the liquefied gas storage tank to the high-pressure consumer. In the fourth mode, the evaporation gas of the liquefied gas storage tank and the liquefied gas of the liquefied gas storage tank are supplied to the high- Gas is supplied to the high-pressure consumer and the oil in the oil storage tank is also supplied to the high-pressure consumer.
The liquefied gas processing system according to the present invention optimally uses the available fuel provided by the ship according to the situation of the ship, thereby reducing the waste of the evaporated gas and efficiently using the energy consumed by the ship There is an effect that the fuel cost of the ship is saved.

Description

Description of the Related Art A Treatment System Of Liquefied Gas

The present invention relates to a liquefied gas processing system.

A ship is a means of transporting large quantities of minerals, crude oil, natural gas, or more than a thousand containers. It is made of steel and buoyant to float on the water surface. ≪ / RTI >

Such a vessel generates thrust by driving the engine. In this case, the engine uses gasoline or diesel to move the piston so that the crankshaft is rotated by the reciprocating motion of the piston, so that the shaft connected to the crankshaft is rotated to drive the propeller It was common.

In recent years, however, LNG fuel supply systems for driving an engine using LNG as a fuel have been used in an LNG carrier carrying Liquefied Natural Gas (LNG) It is also applied to other ships.

In general, LNG is a clean fuel and reserves are richer than petroleum, and its use is rapidly increasing as mining and transportation technology develops. This LNG is generally stored in a liquid state at a temperature of -162 ° C. or below under 1 atm. The volume of liquefied methane is about one sixth of the volume of methane in a gaseous state, The specific gravity is 0.42, which is about one half of that of crude oil. However, the temperature and pressure required to drive the engine may be different from the state of the LNG stored in the tank. Therefore, the technology of controlling the temperature and pressure of the LNG stored in the liquid state and supplying it to the engine is being studied.

SUMMARY OF THE INVENTION The present invention has been made to solve the problems of the prior art as described above, and it is an object of the present invention to provide a system and method for efficiently optimizing the use of evaporation gas, liquefied gas, And to provide a liquefied gas processing system for use with the apparatus.

It is also an object of the present invention to provide a liquefied gas processing system for preventing oil accumulation on a system by providing an oil separator at the rear end of an evaporative gas compressor.

A liquefied gas processing system according to an embodiment of the present invention includes: an evaporation gas supply line connecting a high-pressure consumer in a liquefied gas storage tank to supply an evaporation gas; An evaporative gas compressor provided on the evaporative gas supply line for multi-stepping the evaporative gas; An evaporation gas branch line for supplying an evaporation gas pressurized by at least a part of the evaporation gas compressor to a low pressure consumer site; A liquefied gas supply line connecting the high-pressure consumer to the liquefied gas storage tank to supply liquefied gas; And an oil supply line connecting the high-pressure consumer at an oil storage tank. In the first mode, the evaporation gas of the liquefied gas storage tank is supplied to the low-pressure consumer, and in the second mode, And supplies the evaporated gas of the liquefied gas storage tank to the high-pressure consumer. In the fourth mode, the evaporation gas of the liquefied gas storage tank and the liquefied gas of the liquefied gas storage tank are supplied to the high- Gas is supplied to the high-pressure consumer and the oil in the oil storage tank is also supplied to the high-pressure consumer.

Specifically, the first mode is a case in which the ship loads or unloads the liquefied gas, the second mode is a mode in which the ship is operated at a predetermined speed or less, And the third mode is a case in which the ship is traveling at the predetermined speed or more and the fourth mode is a case in which the ship is traveling at the maximum speed .

Specifically, the predetermined speed may be within a predetermined range including a half speed of the maximum speed of the ship.

Specifically, the predetermined speed may be within a predetermined range including an average speed of the ship.

Specifically, the system further includes a shaft generator driven by the high-pressure consumer, wherein the high-pressure consumer is a high-pressure gas injection engine, the low-pressure consumer is a DFDE, a liquefier or a GCU, 4 mode, the high-pressure consumer can also drive the shaft generator.

An auxiliary pump provided in the liquefied gas supply line and supplying the liquefied gas to the high pressure consumer; A main pump for supplying liquefied gas from the auxiliary pump and compressing the liquefied gas at a high pressure; And a heat exchanger for supplying and heating the liquefied gas from the main pump.

Specifically, the shaft generator may be driven by using at least a part of the power generated by the high-pressure gas injection engine, the high-pressure gas injection engine being connected to the high-pressure gas injection engine.

Specifically, the evaporative gas compressor is a multi-stage compressor composed of five stages, and the evaporative gas branch line can be branched between the second stage and the third stage of the evaporative gas compressor.

Specifically, in the first mode, the DFDE can be preferentially driven.

More specifically, when the supply amount of the evaporation gas is larger than the required amount of the DFDE, it can be sequentially driven in the order of the remelting apparatus and the GCU.

Specifically, in the 2a mode, the high-pressure gas injection engine and the DFDE are simultaneously driven, and when the supply amount of the evaporation gas is larger than the required amount of the DFDE, the re-liquefier and the GCU can be sequentially driven have.

Specifically, in the second mode, the high-pressure gas injection engine, the shaft generator, and the DFDE are driven at the same time, and the amount of evaporation gas required by the high-pressure gas injection engine and the amount of evaporation gas required by the DFDE When the supplied amount is large, the remelting device can be driven.

Specifically, in the third mode, only the high-pressure gas injection engine and the shaft generator can be driven.

The liquefied gas processing system according to the present invention optimally uses the available fuel provided by the ship according to the situation of the ship, thereby reducing the waste of the evaporated gas and efficiently using the energy consumed by the ship There is an effect that the fuel cost of the ship is saved.

Further, the liquefied gas processing system according to the present invention has an oil separator at the downstream side of the evaporative gas compressor to prevent oil accumulation on the system, thereby preventing contamination and improving reliability of system operation, The load of the compressor is reduced and the compression efficiency of the evaporation gas is increased.

1 is a conceptual diagram of a liquefied gas processing system according to a first embodiment of the present invention.
2 is a conceptual diagram of a liquefied gas processing system according to a second embodiment of the present invention.
3 is a conceptual diagram of a liquefied gas processing system according to a third embodiment of the present invention.
4 is a conceptual diagram of a liquefied gas processing system according to a fourth embodiment of the present invention.
5 is a conceptual diagram of a liquefied gas processing system according to a fifth embodiment of the present invention.
6 is a conceptual diagram of an evaporative gas compressor of a liquefied gas processing system according to a fifth embodiment of the present invention.
7 is a conceptual diagram of a liquefied gas processing system according to a sixth embodiment of the present invention.
8 is a graph relating to driving of the liquefied gas processing system of the present invention depending on the amount of evaporation gas generated.

BRIEF DESCRIPTION OF THE DRAWINGS The objects, particular advantages and novel features of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. It should be noted that, in the present specification, the reference numerals are added to the constituent elements of the drawings, and the same constituent elements are assigned the same number as much as possible even if they are displayed on different drawings. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

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

1 is a conceptual diagram of a liquefied gas processing system according to a first embodiment of the present invention.

1, a liquefied gas processing system 1 according to a first embodiment of the present invention includes a liquefied gas storage tank 10, a customer 20, a pump 30, a heat exchanger 40, A gas compressor (50), and an oil storage tank (60).

Hereinafter, the liquefied gas may be used to encompass all gaseous fuels generally stored in a liquid state, such as LNG or LPG, ethylene, ammonia, etc. In the case where the gas is not in a liquid state by heating or pressurization, . This also applies to the evaporative gas. In addition, LNG can be used to mean not only NG (Natural Gas) in liquid state but also NG in supercritical state for convenience, and evaporation gas can be used to include not only gaseous evaporation gas but also liquefied evaporation gas have.

The liquefied gas storage tank (10) stores liquefied gas to be supplied to the customer (20). The liquefied gas storage tank 10 must store the liquefied gas in a liquid state, at which time the liquefied gas storage tank 10 may have the form of a pressure tank.

The liquefied gas storage tank 10 includes an outer tank (not shown), an inner tank (not shown), and a heat insulating portion (not shown). The outer tank is a structure that forms the outer wall of the liquefied gas storage tank 10, and may be formed of steel, and may have a polygonal cross section.

The inner tank is provided inside the outer tank, and can be supported and supported inside the outer tank by a support (not shown). At this time, the support may be provided on the lower end of the inner tank, and may be provided on the side of the inner tank for suppressing lateral movement of the inner tank.

The inner tank can be made of stainless steel and can be designed to withstand pressures from 5 bar to 10 bar (6 bar, for example). The reason why the inner tank is designed to withstand such a constant pressure is that the inner pressure of the inner tank can be increased as the liquefied gas contained in the inner tank is evaporated and the evaporation gas is generated.

A baffle (not shown) may be provided in the inner tank. The baffle means a plate in the form of a lattice. As the baffle is installed, the pressure inside the tank can be evenly distributed to prevent the tank pressure from being concentrated to a part of the tank.

The heat insulating portion is provided between the inner tank and the outer tank and can prevent the external heat energy from being transmitted to the inner tank. At this time, the heat insulating portion may be in a vacuum state. By forming the thermal insulation in a vacuum, the liquefied gas storage tank 10 can withstand higher pressures more efficiently than a conventional tank. For example, the liquefied gas storage tank 10 can sustain a pressure of 5 to 20 bar through the vacuum insulation.

As described above, in this embodiment, the use of the pressure tank type liquefied gas storage tank 10 having a vacuum type heat insulating portion between the outer tanks and the inner tank makes it possible to minimize the generation of the evaporated gas, It is possible to prevent a problem such as breakage of the storage tank 10 from occurring.

An evaporative gas supply line 11 for supplying an evaporative gas and a liquefied gas supply line 13 for supplying liquefied gas are provided between the liquefied gas storage tank 10 and the customer 20 in the first embodiment of the present invention And the evaporation gas branch line 12 may be branched on the evaporation gas supply line 11. [

The evaporation gas supply line 11 may include an evaporation gas compressor 50 between the liquefied gas storage tank 10 and the consumer 20 so that the evaporation gas pressurized by the multi- . At this time, the consumer 20 supplied by the evaporation gas supply line 11 may be the high-pressure consumer 21.

The evaporation gas branch line 12 is branched from the second stage and the third stage of the evaporation gas compressor 50 provided in the evaporation gas supply line 12 and connected to the customer 20, Can supply. At this time, the consumer 20 supplied by the evaporation gas branch line 12 may be the low-pressure consumer 22.

The liquefied gas supply line 13 may include a pump 30 and a heat exchanger 40 between the liquefied gas storage tank 10 and the customer 20 so that the liquefied gas compressed at a high pressure And can be supplied to the customer 20. At this time, the consumer 20 supplied by the liquefied gas supply line 13 may be the high-pressure consumer 21.

At this time, a supply valve (not shown) is provided in each of the evaporation gas supply line 11, the evaporation gas branch line 12 and the liquefied gas supply line 13 so that the supply amount of the evaporation gas Lt; / RTI >

The customer 20 is driven through the liquefied gas or the evaporation gas supplied from the liquefied gas storage tank 10 or the oil supplied from the oil storage tank 06 to be described later. That is, the customer 20 requires evaporation gas, liquefied gas, or oil, and may include all devices and mechanisms driven by the raw material.

As the piston 20 (not shown) in the cylinder (not shown) reciprocates by the combustion of the liquefied gas, the evaporation gas or the oil, the consumer 20 rotates the crankshaft (not shown) connected to the piston, A shaft (not shown) connected to the crankshaft can be rotated. Therefore, as the propeller (not shown) connected to the shaft rotates when the consumer 20 is driven, the hull can move forward or backward.

Of course, in this embodiment, the customer 20 may be an engine for driving the propeller, but it may be an engine for generating power or an engine for generating other power. In other words, the present embodiment does not particularly limit the kind of the consumer 20. However, the customer 20 may be an internal combustion engine that generates a driving force by the combustion of the evaporative gas and the flash gas.

The consumer 20 may include a high-pressure consumer 21 and a low-pressure consumer 22.

The high pressure consumer 21 may be a gaseous fuel engine with a high pressure gas injection engine (e.g., MEGI) and may be supplied with a liquefied or vaporized gas in a supercritical state (30 to 60 degrees Celsius, 200 to 400 bar) And the state of the liquefied gas or the evaporated gas to be supplied may vary depending on the state required by the high-pressure gas injection engine.

The high pressure consumer 21 may have dual fuel available. An engine that can use dual fuel is a two-stroke engine, typically driven by a diesel cycle. In this diesel cycle, air is compressed by the piston, the compressed high-temperature air is ignited by the pilot fuel, and the remaining high-pressure gas is injected to cause the explosion.

In this case, HFO (Heavy Fuel Oil) or MDO (Marine Diesel Oil) is used as the ignition fuel, and the ratio of the ignition fuel to the high-pressure gas is about 5:95, and the injection amount of the ignition fuel can be adjusted from 5 to 100% Do. Therefore, the ignition fuel is also usable as the driving fuel for the engine.

That is, when the injection amount of the ignition fuel is about 5%, evaporative gas (or heated liquefied gas; about 95%) is mainly used as the engine driving fuel, and when the injection amount of the ignition fuel is 100% When all the fuel (oil) is used and the injection quantity of the ignition fuel is between 5 and 100%, the ignition fuel (oil) and the evaporation gas (or the heated liquefied gas) are mixed and used as the engine driving fuel.

In the case where the high-pressure consumer 21 is an engine, the shaft generator 23 may be installed on a shaft driven by the engine. The shaft generator 23 can be engaged with and engaged with the engine, generate power from the engine, and supply electric power to the electric equipment (not shown).

At this time, the shaft generator 23 gives resistance to the drive of the engine, which increases the output to the engine (not shown), but does not increase the speed and further increases the evaporation gas Gas) can be consumed.

It is possible to solve the environmental problem due to the incineration of the evaporative gas and to efficiently utilize the surplus resources through the process in which the evaporator gas is consumed by the shaft generator 23 and the electric power is produced thereby making it possible to economically operate the ship.

The low-pressure consumer 22 may be a DFDE, a liquefier or a gas-fired unit (GCU). The low-pressure consumer 22 is a consumer 20 using a low-pressure evaporation gas, which is compressed in two or three stages by an evaporation gas compressor 50 to be described later and is about 7 to 15 bar, for example, a DFDE engine .

In the case of a DFDE engine, liquefied gas and fuel oil (oil) can be selectively supplied without being supplied with a mixture of liquefied gas and fuel oil. This is to prevent the mixture of two materials having different combustion temperatures from being mixed, thereby preventing the efficiency of the engine from deteriorating.

The consumer 20 described above is, for example, an engine. The consumer 20 is not limited to this, and can be applied to various places where liquefied gas is needed.

That is, the customer 20 may be a gas turbine (not shown). At this time, the gas turbine can receive the low-pressure evaporative gas supplied from the liquefied gas storage tank 10 and consume it, and can be included in the low-pressure consumer 22.

The power generated by the gas turbine can rotate the propeller (not shown) or the like to advance or backward the ship (not shown).

The pump 30 is provided on the liquefied gas supply line 13 and pressurizes the liquefied gas discharged from the liquefied gas storage tank 10. The pump 30 may include an auxiliary pump 31 and a main pump 32. [

The auxiliary pump 31 may be provided on the liquefied gas supply line 13 between the liquefied gas storage tank 10 and the main pump 32 so that a sufficient amount of liquefied gas is supplied to the main pump 32 So that cavitation of the main pump 32 can be prevented.

In addition, the auxiliary pump 31 can pressurize the liquefied gas from the liquefied gas storage tank 10 to several to several tens of bars or less, and the liquefied gas through the auxiliary pump 31 is pressurized from 1 to 25 bar .

The liquefied gas stored in the liquefied gas storage tank 10 is in a liquid state. At this time, the auxiliary pump 31 may pressurize the liquefied gas discharged from the liquefied gas storage tank 10 to slightly increase the pressure and the temperature, and the liquefied gas pressurized by the auxiliary pump 31 may still be in a liquid state .

At this time, the auxiliary pump 31 can be provided in the liquefied gas storage tank 10 and can assume a sleeping shape.

The main pump 32 pressurizes the liquefied gas discharged from the liquefied gas storage tank 10 at a high pressure to be supplied to the customer 20. The liquefied gas is discharged from the liquefied gas storage tank 10 at a pressure of about 10 bar and is firstly pressurized by the auxiliary pump 31. The main pump 32 is supplied with the liquid liquefied by the auxiliary pump 310 Gas is supplied to the heat exchanger (40).

At this time, the main pump 32 pressurizes the liquefied gas to a pressure required by the customer 20, for example, 200 bar to 400 bar (preferably 300 bar) to supply the liquefied gas to the customer 20 (preferably the high-pressure customer 21) So that the consumer 20 can consume the liquefied gas.

The main pump 32 is configured to pressurize the liquid liquefied gas discharged from the auxiliary pump 31 at a high pressure so that the liquefied gas becomes a supercritical state having a temperature higher than the critical point and a high pressure . At this time, the temperature of the liquefied gas in the supercritical state may be below minus 20 degrees Celsius, which is relatively higher than the critical temperature.

Alternatively, the main pump 32 can pressurize the liquefied gas in the liquid state to a supercooled liquid state by pressurizing it at a high pressure. Here, the supercooled liquid state means a state where the pressure of the liquefied gas is higher than the critical pressure and the temperature is lower than the critical temperature.

Specifically, the main pump 32 pressurizes the liquid-state liquefied gas discharged from the auxiliary pump 31 at a high pressure of 200 to 400 bar so that the temperature of the liquefied gas becomes lower than the critical temperature, Phase state to a liquid state. Here, the temperature of the liquefied gas in the subcooled liquid state may be minus 140 degrees Celsius to minus 60 degrees Celsius, which is relatively lower than the critical temperature.

The heat exchanger 40 is provided on the liquefied gas supply line 13 between the customer 20 and the pump 30 and exchanges the liquefied gas supplied from the pump 30. The pump 30 for supplying the liquefied gas to the heat exchanger 40 may be the main pump 32 and the heat exchanger 40 may be configured to discharge the liquefied gas in the subcooled liquid state or the supercritical state from the main pump 32 Exchanged under the pressure of 200 bar to 400 bar, converted into liquefied gas in a supercritical state of 30 to 60 degrees Celsius, and then supplied to the customer 20.

The evaporative gas compressor (50) can pressurize the evaporated gas generated in the liquefied gas storage tank (10). The evaporation gas compressor 50 can supply the evaporation gas generated in the liquefied gas storage tank 10 and discharged at a pressure of about 10 bar to the consumer 20 at a pressure of 200 to 400 bar.

A plurality of evaporation gas compressors (50) may be provided to pressurize the evaporation gas at multiple stages. For example, the evaporation gas compressor 50 is provided with an evaporation gas first stage compressor 51, an evaporation gas second stage compressor 52, an evaporation gas third stage compressor 53, A gas fourth-stage compressor 54, and an evaporation gas fifth-stage compressor 55, so that the evaporation gas can be pressurized in five stages.

Specifically, the evaporative gas compressor 50 is introduced at about 1.05 bar in the liquefied gas storage tank 10 and is pressurized to about 5 bar in the evaporative gas first stage compressor 51, and the evaporative gas second stage compressor 52 The evaporation gas is compressed to about 150 bar at the fourth-stage compressor 54, the second evaporator 50 is compressed at about 300 bar at the fifth-stage compressor 55, Lt; / RTI >

However, the pressure of the evaporative gas discharged from each stage described above is not limited to one example, and can be changed through a separate operation.

The evaporated gas pressurized by the evaporation gas second stage compressor 52 is supplied to the low pressure consumer 22 through the evaporation gas branch line 12 or is supplied to the evaporation gas third stage compressor 12 through the evaporation gas supply line 11, Stage compressor (55) can be supplied to the high-pressure consumer 21 by the evaporation gas supply line 11. The evaporation gas is supplied to the high-pressure consumer 21 via the evaporation gas supply line 11. [

The evaporation gas branch line 12 is connected between the evaporation gas compressor 50 on the evaporation gas supply line 11 at one end and can supply the pressurized evaporation gas to the low pressure consumer 22. For example, when five evaporative gas compressors 50 are provided, an evaporative gas branch line 12 may be connected between the evaporative gas second stage compressor 52 and the evaporative gas third stage compressor 53.

Therefore, the evaporated gas pressurized by the evaporative gas second stage compressor 52 can be branched and supplied to the low-pressure consumer 22 or the high-pressure consumer 21, respectively.

The evaporated gas that has been pressurized five times from the evaporation gas first stage compressor 51 to the evaporation gas fifth stage compressor 55 can be supplied to the high pressure consumer 21 through the evaporation gas supply line 11. Here, the evaporation gas supplied to the evaporation gas supply line 11 and the liquefied gas supplied to the liquefied gas supply line 13 may be mixed and supplied to the high-pressure consumer 21. To this end, a mixer (not shown) may be provided upstream of the high-pressure consumer 21.

Between the evaporative gas compressors 51 to 55 at each stage, an evaporative gas cooler (not shown) may be provided. When the evaporation gas is pressurized by the evaporation gas compressor 50, the temperature can also be raised according to the pressure increase. Therefore, in this embodiment, the evaporation gas cooler can be used to lower the temperature of the evaporation gas again.

The evaporative gas cooler may be installed in the same number as that of the evaporative gas compressor 50, and each evaporative gas cooler may be provided downstream of each of the evaporative gas compressors 51 to 55.

The evaporation gas compressor 50 pressurizes the evaporation gas in order to increase the liquefaction efficiency of the evaporation gas. Evaporation gas increases the boiling point when the pressure rises, which means that it can be liquefied even at relatively high temperatures. Therefore, this embodiment can increase the pressure of the evaporation gas to the evaporation gas compressor 50, so that the evaporation gas can be easily liquefied. At this time, the evaporated gas discharged from the evaporating gas compressor (50) located at the end based on the flow of the evaporating gas may have a pressure of 200 to 400 bar.

However, the evaporated gas discharged from the second evaporator second compressor (52) located upstream of the evaporative gas branch line (12) can have a pressure required by the low pressure consumer (22) The pressure may be between 1 and 50 bar.

The oil storage tank (60) stores the oil to be supplied to the customer (20). Specifically, the oil storage tank 60 can supply oil to the high-pressure consumer 21 by an oil pump (not shown).

The oil storage tank 60 can store the oil at a normal temperature in a liquid state, can prevent an external impact, and can be designed to facilitate storage of oil.

An oil supply line 14 for supplying oil may be installed between the oil storage tank 60 and the consumer 20 in the first embodiment of the present invention.

Specifically, the oil supply line 14 can directly connect the oil storage tank 60 and the high-pressure consumer 21 and can merge on the evaporation gas supply line 11 or can be connected to the evaporation gas supply line 11, It is possible to indirectly connect the oil storage tank 60 and the high-pressure consumer 21 by joining together at the point where the gas supply lines 13 join.

At this time, the oil supply line 14 is provided with an oil supply valve 61, and the supply amount of the oil can be adjusted according to the opening degree adjustment of the oil supply valve 61.

The oil supply valve 61 is composed of a three-way valve and is capable of connecting the oil supply line 61 and the evaporation gas supply line 11 and is composed of a four-way valve and is connected to the oil supply line 61, And the evaporation gas supply line 11 can be connected.

Before describing the driving of the liquefied gas processing system 1 according to the first embodiment of the present invention, driving control of the liquefied gas processing system 1 will be described with reference to Fig.

8 is a graph relating to driving of the liquefied gas processing system of the present invention depending on the amount of evaporation gas generated. The horizontal axis is the speed of the ship (unit is Knot), and the vertical axis is the amount of evaporation gas generation (unit: kg / hr).

Referring to FIG. 8, the amount of evaporative gas consumption of the engine is compared with the volume of the liquefied gas storage tank according to the speed of the ship, which changes while the ship (not shown) travels from the departure point to the destination.

The liquefied gas is shipped to the liquefied gas storage tank 10 of the ship in the first mode, the ship departs from the origin at a low speed in the second mode, the ship is operated from the origin to the destination in the third and fourth modes, 2 mode, the ship arrives at a low speed to the destination, and in the first mode, the liquefied gas is unloaded from the liquefied gas storage tank 10 of the ship.

The first mode shows a case where the ship loads or unloads the liquefied gas.

In the first mode, the amount of evaporation gas generated is such that the evaporation gas is generated according to the loading or unloading of the liquefied gas, but it can be discharged or removed through a separate process, and the speed of the ship is not limited to the shipment (Not shown) at a very low speed so as to be located at the leftmost position.

From the second mode to the fourth mode, the evaporation gas generation amount is constantly generated, and thus the laden evaporation gas generation amount c is represented by a horizontal straight line.

In the 2a mode, only the MEGI engine is driven and the MEGI gas consumption amount (a) is displayed to increase with a specific slope. From the 2b mode to the 4th mode, the MEGI engine and the shaft generator 23 are simultaneously driven. The + SG gas consumption (b) is displayed to increase with a certain slope from the point where the MEGI gas consumption amount (a) is discontinuously discretely spaced upward.

Therefore, in the embodiment of the present invention, the difference between the laden evaporation gas generation amount c and the MEGI gas consumption amount a, or the difference between the MEGI + SG gas consumption amount b and the Laden evaporation gas generation amount c, The optimum efficiency of the use of the evaporative gas can be derived, which is described below.

The first mode is a case where the ship loads or unloads the liquefied gas. In this first mode, since the amount of evaporative gas generated in the liquefied gas storage tank 10 is not small, the evaporated gas in the liquefied gas storage tank 10 is supplied to the low-pressure consumer 22.

In the first mode, the evaporation gas is supplied to the low-pressure consumer 22, and at this time, the DFDE of the low-pressure consumer 22 can be preferentially driven. The evaporation gas to which the DFDE is supplied is preferentially consumed and when the amount of evaporation gas generated in the liquefied gas storage tank 10 is larger than the evaporated gas amount consumed by the DFDE, the re-liquefying device (not shown) of the low- (GCU) is further driven when the amount of evaporative gas generated in the liquefied gas storage tank 10 is larger than the sum of the amount of evaporative gas consumed by the refueling apparatus and the amount of evaporative gas consumed by the DFDE.

The second mode is operated at a low speed when the ship departs from the departure point or arrives at the destination, so that the evaporation gas amount required by the customer 20 is smaller than the evaporation gas generation amount generated in the liquefied gas storage tank 10 And will travel at or below the pre-set speed.

The second mode includes an 2a mode in which the ship is traveling at a predetermined speed or less and a 2b mode in which the ship is traveling at a predetermined speed. In this second mode, the evaporated gas of the liquefied gas storage tank 10 is supplied to the high-pressure consumer 21 and the low-pressure consumer 22.

The evaporation gas of the liquefied gas storage tank 10 is simultaneously supplied to the high-pressure consumer 21 and the low-pressure consumer 22 so that the high-pressure gas injection engine of the high-pressure consumer 21 and the DFDE Are simultaneously driven. At this time, when the amount of evaporated gas generated in the liquefied gas storage tank 10 is larger than the amount of evaporated gas consumed by the high-pressure gas injection engine and the DFDE, the re-liquefaction device of the low-pressure consumer 22 is driven, When the amount of evaporated gas generated in the liquefied gas storage tank 10 is smaller than the total amount of evaporated gas consumed by the high-pressure gas injection engine, the gas combustion apparatus is further driven.

In the second mode, the evaporated gas in the liquefied gas storage tank 10 is simultaneously supplied to the high-pressure consumer 21 and the low-pressure consumer 22. In the high-pressure consumer 21, the high-pressure gas injection engine is driven, 23 are also driven together.

The amount of evaporative gas generated in the liquefied gas storage tank 10 is larger than the sum of the evaporative gas amount consumed by the high-pressure gas injection engine driven by the high-pressure consumer 21 and the evaporative gas consumed by the DFDE driven by the low- In many cases, the liquefaction device of the low-pressure consumer 22 can be driven.

In the third and fourth modes, the ship is traveling at medium or high speed while the ship is navigating from the departure point to the destination point. In this case, the customer 20 takes a high load in order to increase the speed of the ship and accordingly requires a large amount of evaporation gas. The amount of evaporated gas consumed by the customer 20 is larger than the amount of evaporation gas generated in the liquefied gas storage tank 10 More.

The third mode is a case where the ship is operated at a predetermined speed or higher. In this third mode, the evaporated gas of the liquefied gas storage tank 10 is supplied to the high-pressure consumer 21. In the third mode, since the evaporated gas in the liquefied gas storage tank 10 is supplied only to the high-pressure consumer 21, the high-pressure gas injection engine in the high-pressure consumer 21 is driven and the shaft generator 23 is also driven .

The fourth mode is a case where the ship is operating at the maximum speed. In this fourth mode, the oil in the oil storage tank 60 is supplied to the high-pressure consumer 21 together with the evaporation gas and liquefied gas of the liquefied gas storage tank 10. In the fourth mode, the high-pressure gas injection engine is driven by the high-pressure consumer 21 and the shaft generator 23 is also driven.

Here, the preset speed may be a predetermined range including half the maximum speed of the ship. Specifically, the predetermined range may be 95% to 105% of the maximum speed half value of the ship or 90% to 110% of the maximum speed half value of the ship.

In addition, the predetermined speed may be a predetermined range including the average speed of the ship. Specifically, the predetermined range may be 95% to 105% of the average speed of the ship or 90% to 110% of the average speed of the ship.

As described above, the liquefied-gas treatment system 1 according to the first embodiment of the present invention optimally uses the available fuel provided by the ship in accordance with the situation of the ship, thereby reducing the waste of the evaporated gas, The efficient use of the energy consumed has the effect of saving the fuel cost of the vessel.

2 is a conceptual diagram of a liquefied gas processing system according to a second embodiment of the present invention.

2, the liquefied gas processing system 2 according to the second embodiment of the present invention includes a liquefied gas storage tank 10, a customer 20, a pump 30, a heat exchanger 40, A gas compressor (50), and an oil storage tank (60).

In the second embodiment of the present invention, the components are the same as those in the liquefied gas processing system 1 except for the evaporative gas compressor 50 in the first embodiment of the present invention, It does not refer to it.

The evaporative gas compressor (50) may be provided on the evaporative gas supply line (11), and a plurality of evaporative gas compressors (50) may be provided in parallel. Two evaporation gas compressors 50 each having five stages may be provided in parallel between the liquefied gas storage tank 10 and the demander 20 on the evaporation gas supply line 11.

In the second embodiment of the present invention, when the ship is operated at a speed higher than a predetermined speed, that is, in the case of the fourth mode, all of the plurality of evaporative gas compressors 50 are driven and the pressurized evaporative gas is supplied to the high- A fourth mode in which a plurality of evaporative gas compressors 50 are driven and the evaporated gas pressurized in at least one of the plurality of evaporative gas compressors 50 is supplied to the low pressure consumer 22 and the remaining evaporated gas is supplied to the high pressure consumer 21 A fourth mode in which the evaporation gas of the liquefied gas storage tank 10 and the liquefied gas are simultaneously supplied to the high pressure consumer 21, the evaporation gas of the liquefied gas storage tank 10 and the oil storage tank And the fourth d mode in which the oil in the second diesel engine 60 is supplied to the high-pressure consumer 21, to drive the liquefied gas processing system 2.

A considerable amount of evaporative gas is generated in the liquefied gas storage tank 10 since a considerable time has passed since departure from the departure point while the ship was traveling from the departure point to the destination point. Thus, since a sufficient amount of fuel is provided for the ship to be driven, the ship can be driven at the maximum speed for the rapid conveyance of goods.

In the case where the ship is operated at the highest speed, since the amount of evaporative gas stored in the liquefied gas storage tank 10 is the largest, the 4a mode is executed first, and the liquefied gas amount consumed by the demand- When the amount of evaporated gas generated in the gas storage tank 10 is large, the 4b mode is performed.

 When the amount of evaporated gas generated in the liquefied gas storage tank 10 is smaller than the amount of evaporated gas consumed by the consumer 20 during the execution of the 4a mode, the 4c mode or the 4d mode can be performed.

At this time, if the internal pressure of the liquefied gas storage tank 10 is higher than the preset pressure, the 4c mode is performed. If the internal pressure of the liquefied gas storage tank 10 is lower than the preset pressure, the 4d mode can be performed.

In the case of driving the high pressure consumer 21 in the drive of the 4a mode to the 4d mode as described above, the high-pressure gas injection engine may be driven and the shaft generator 23 may be driven at the same time.

Here, the predetermined speed may be within a predetermined range including the maximum speed of the ship, and the predetermined range may be 95% to 105% of the maximum speed of the ship or 90% to 110% of the maximum speed of the ship.

The control of the liquefied gas processing system 2 in the second embodiment of the present invention can be freely applied to, but not limited to, specifically controlling the fourth mode in the first embodiment of the present invention.

As described above, the liquefied-gas treatment system 2 according to the second embodiment of the present invention optimally uses the available fuel provided by the ship in accordance with the situation of the ship, thereby reducing the waste of the evaporated gas, The efficient use of the energy consumed has the effect of saving the fuel cost of the vessel.

3 is a conceptual diagram of a liquefied gas processing system according to a third embodiment of the present invention.

3, the liquefied gas processing system 3 according to the third embodiment of the present invention includes a liquefied gas storage tank 10, a customer 20, a pump 30, a heat exchanger 40, A gas compressor (50), and an oil storage tank (60).

In the third embodiment of the present invention, the constituent elements are the same as those of the evaporative gas compressor 50 in the liquefied gas processing system 1 according to the first embodiment of the present invention, It does not refer to it.

The evaporative gas compressor (50) may be provided on the evaporative gas supply line (11), and a plurality of evaporative gas compressors (50) may be provided in parallel. Two evaporation gas compressors 50 each having five stages may be provided in parallel between the liquefied gas storage tank 10 and the demander 20 on the evaporation gas supply line 11.

The evaporative gas compressor 50 includes first through fifth bypass lines 511, 521, 531, 541, 551 and first through fifth bypass valves 512, 522, 532, 542, 552.

The first bypass line 511 is branched between the evaporation gas first stage compressor 51 and the evaporation gas second stage compressor 52 on the evaporation gas supply line 11 and evaporated on the evaporation gas supply line 11 It is possible to merge upstream of the gas first stage compressor (51).

The first bypass line 511 may include a first bypass valve 512 to bypass the evaporation gas through opening regulation according to the evaporative gas compressible capacity of the evaporative gas second stage compressor 52 .

The second to fourth bypass lines 521, 531 and 541 are connected to the second to fourth-stage compressors 52, 53 and 54 and the third to fifth-stage compressors 53, 54 and 55, respectively, on the evaporation gas supply line 11, Stage compressors 51, 52 and 53 and the evaporation gas second-stage to fourth-stage compressors 52, 53 and 54, respectively, on the evaporation gas supply line 11 have.

The second to fourth bypass lines 521, 531 and 541 are provided with second to fourth bypass valves 522, 532 and 542, respectively, and are connected to the evaporative gas compressible capacity of the third to fifth evaporator gas compressors 53, The evaporation gas can be bypassed through the opening control.

The fifth bypass line 551 is branched downstream of the evaporation gas fifth stage compressor 55 on the evaporation gas supply line 11 and is connected to the evaporation gas fourth stage compressor 54 and the evaporation gas fifth stage compressor 55 ). ≪ / RTI >

The fifth bypass line 551 is provided with a fifth bypass valve 552 and is capable of bypassing the evaporative gas through opening regulation according to the required pressure of the demander 20, have.

In the third embodiment of the present invention, the bypass control for controlling the evaporative gas compressor 50 during the control of the liquefied gas processing systems 1 and 2 in the first and second embodiments of the present invention The details will be described below.

The first to fourth modes may be the same as or similar to those described in the first and second embodiments of the present invention, and the first to fourth modes may be the same or similar to those described in the first and second embodiments of the present invention Let's change the contents.

In the first mode, a portion of the upstream side of the evaporative gas compressor (50) can bypass the evaporative gas above the preset pressure of each stage and bypass the evaporative gas downstream of the evaporative gas compressor (50) .

Specifically, in the first mode, the evaporator gas first and second compressors 51 and 52 open the first and second bypass valves 512 and 522 at the first and second preset pressures respectively , The evaporation gas third to fifth compressors 53, 54, and 55 open the third to fifth bypass valves 532, 542, and 552 during the first mode driving irrespective of the predetermined pressure of each stage .

Here, the first preset pressure may have a preliminarily fixed pressure value (fixed discharge pressure (preliminary set point: 150 bar)) of about 150 bar, and the second preset pressure may be a pressure And may be changed according to the value of the second discharge pressure of the evaporated gas to be discharged.

That is, in the first mode, since the evaporation gas is not to be pressurized by the third to fifth compressors 53, 54, 55, the opening of the third to fifth bypass valves 532, 542, Can be controlled so as not to be compressed.

In the second mode, the evaporation gas compressor 50 can bypass the evaporation gas above the preset pressure of each stage.

Specifically, in the second mode, the first to fifth compressors 51, 52, 53, 54, and 55 of the evaporation gas compress the first to fifth bypass valves 512, 522, 532, ) Can be opened.

Here, the first preset pressure may be changed according to the pressure (MEGI required Set Pressure) required by the high pressure consumer 21, and the second preset pressure may be changed according to the evaporation gas discharged from the evaporation gas second stage compressor 52 And the third to fifth preset pressures may be changed according to the interstage pressure of the third to fifth compressors 53, 54, .

That is, in the second mode, since the evaporation gas must be supplied to both the high-pressure consumer 21 and the low-pressure consumer 22 at a pressure required by each customer 20, the first through fifth bypass valves 512, 522, 532, May open the valves 512, 522, 532, 542, and 552 at the first to fifth preset pressures to prevent excessive pressure from being applied to each end of the evaporative gas compressor 50.

In the third mode, a part of the upstream side of the evaporative gas compressor (50) can bypass the evaporation gas at a predetermined pressure or more of each stage.

Specifically, in the third mode, the evaporation gas first stage compressor 51 opens the opening of the first bypass valve 512 at a first predetermined pressure or higher, and the evaporation gas second- 52, 53, 54, 55 may close the opening of the second to fifth bypass valves 522, 532, 542, 552.

Here, the first preset pressure may be changed according to the pressure value required by the high pressure consumer 21 (gas pressure set point required by MEGI), and the second preset pressure may be changed by the evaporator gas second stage compressor 52 (Second discharge pressure) value of the evaporating gas.

That is, in the third mode, the first and second bypass valves 512 and 522 in the first and second compressors 51 and 52 are operated at a predetermined pressure higher than the preset pressure for supplying the low- And the evaporation gas third to fifth compressors 53, 54 and 55 pressurize and supply the evaporation gas to the high pressure consumer 21 as much as possible. Therefore, the third to fifth bypass valves (532, 542, 552) are all closed, and the evaporation gas compressors (53, 54, 55) at each stage are loaded with high load.

In modes 4a and 4b, one evaporative gas compressor of the plurality of parallelly connected evaporative gas compressors 50 closes the opening of the first through fifth bypass valves 512, 522, 532, 542, and 552, The first to fifth bypass valves 512, 522, 532, 542, and 552 can be opened at a fifth preset pressure or more.

That is, the opening of all of the valves 512, 522, 532, 542, and 552 can be closed so that a high load is applied to some compressors of the plurality of evaporative gas compressors 50, and at the same time, The opening of the first to fifth bypass valves 512, 522, 532, 542, and 552 can be opened.

In the fourth c mode, all of the plurality of parallelly connected evaporative gas compressors 50 can close the opening of the first to fifth bypass valves 512, 522, 532, 542, and 552.

That is, the opening of all of the valves 512, 522, 532, 542, and 552 can be closed so that a high load is applied to all of the plurality of evaporative gas compressors 50.

In the fourth d mode, the evaporation gas first-stage compressor 51 opens the opening of the first bypass valve 512 at a first predetermined pressure or higher, and the evaporation gas second-fifth compressors 52, 53 , 54,55 can close the opening of the second to fifth bypass valves 522, 532, 542, and 552.

Here, the first short-time set pressure may be a pressure required by the high-pressure consumer 21, or may be 130 to 170 bar (preferably 150 bar).

The second shortest set pressure may be the pressure required by the low pressure consumer 22.

As described above, the liquefied-gas treatment system 3 according to the third embodiment of the present invention optimally uses the available fuel provided by the ship in accordance with the situation of the ship, thereby reducing the waste of the evaporated gas, The efficient use of the energy consumed has the effect of saving the fuel cost of the vessel.

4 is a conceptual diagram of a liquefied gas processing system according to a fourth embodiment of the present invention.

4, the liquefied gas processing system 4 according to the fourth embodiment of the present invention includes a liquefied gas storage tank 10, a customer 20, a pump 30, a heat exchanger 40, A gas compressor (50), and an oil storage tank (60).

In the fourth embodiment of the present invention, the constituent elements are the same as those in the liquefied gas processing system 4 according to the third embodiment of the present invention.

Since the fourth embodiment of the present invention is the same as or similar to that of the third embodiment of the present invention, the description of the construction is omitted, and the liquefied gas processing systems 1, The bypass control for controlling the evaporative gas compressor 50 in the case where the load of the customer 20 increases or decreases during the control of the evaporative gas compressor 2 will be described in detail below.

In the fourth embodiment of the present invention, the evaporative gas compressor 50 sequentially bypasses from the upstream side to the downstream side when the load of the demander 20 decreases from the predetermined load.

Specifically, when the load of the customer 20 is lower than the predetermined load, the evaporative gas compressor 50 sequentially supplies the evaporative gas from the evaporator gas first stage compressor 51 to the evaporative gas fifth stage compressor 55, The fifth bypass valve 512, 522, 532, 542 or 552 can be opened and the load of the customer 20 is increased more than the predetermined load, the evaporation gas from the fifth-stage compressor 55 to the evaporation gas first stage compressor 51 The first to fifth bypass valves 552, 542, 532, 522 and 512 are closed.

Here, the pre-set load may be a load when the load of the customer 20 is in a normal state, and the steady state may be a state where the load change rate of the consumer 20 is 5% to 10%.

As described above, the liquefied-gas treatment system 4 according to the fourth embodiment of the present invention optimally uses the available fuel provided by the ship in accordance with the situation of the ship, thereby reducing the waste of the evaporated gas, The efficient use of the energy consumed has the effect of saving the fuel cost of the vessel.

5 and 6 are conceptual diagrams of a liquefied gas processing system according to a fifth embodiment of the present invention.

5 and 6, a liquefied gas processing system 5 according to a fifth embodiment of the present invention includes a liquefied gas storage tank 10, a customer 20, a pump 30, a heat exchanger 40 ), And an evaporative gas compressor (50).

In the fifth embodiment of the present invention, each constitution is the same as the constitution except for the evaporative gas compressor 50 in the liquefied gas processing system 1 according to the first embodiment of the present invention, It does not refer to it.

In the fifth embodiment of the present invention, the evaporation gas parallel supply line 11a is further included.

The evaporation gas parallel supply line 11a is branched upstream of the evaporation gas first parallel compressor 51a on the evaporation gas supply line 11 and is connected to the evaporation gas first parallel compressor 51a on the evaporation gas supply line 11, And the evaporation gas second-stage compressor 52. In this case,

The evaporation gas parallel supply line 11a can pass through the evaporation gas first parallel compressor 51a and can include the evaporation gas second parallel compressor 51b.

The evaporation gas parallel supply line 11a is provided with an evaporation gas parallel supply valve (not shown) so that the supply amount of the evaporation gas can be adjusted in accordance with the adjustment of the opening degree of the evaporation gas parallel supply valve.

The evaporative gas compressor (50) may be composed of five stages, for example, and may be constituted by first to fifth evaporator compressors (51, 52, 53, 54, 55).

The evaporation gas first stage compressor 51 may be composed of an evaporation gas first parallel compressor 51a and an evaporation gas second parallel compressor 51b and the evaporation gas first parallel compressor 51a may include a main cylinder 5131, and the evaporative gas second parallel compressor 51b may be provided with an auxiliary cylinder 5132.

That is, at least two first cylinders 513 for compressing and discharging the evaporation gas in the evaporation gas first stage compressor 51 may be provided in parallel.

The first cylinder 513 may be provided with a first unloader valve 514 for controlling the compression capacity and two or more first unloader valves 514 may be provided. For example, when two first cylinders 513 of the evaporator gas first stage compressor 51 are constructed in parallel, two or more unloader valves may be provided for each of the cylinders 5131 and 5132.

That is, when the first cylinder 513 of the evaporation gas first stage compressor 51 is composed of the main cylinder 5131 and the auxiliary cylinder 5132, the main cylinder 5131 is provided with the 1-25 unloader valve 51 unloader valve 5144 and the 1-50 unloader valve 5142 may be provided in the auxiliary cylinder 5132 and the 1-75 unloader valve 5143 and the 1-100 unloader valve 5144 may be provided in the auxiliary cylinder 5132 have.

When the 1-25 unloader valve 5141, the 1-50 unloader valve 5142, the 1-75 unloader valve 5143 and the 1-100 unloader valve 5144 are both opened, The compression capacity of the first stage compressor 51 becomes 0%, the 1-25 unloader valve 5141 is closed, the 1-50 unloader valve 5142, the 1-75 unloader valve 5143, And the 1-100 unloader valve 5144 are opened, the compression capacity of the evaporation gas first stage compressor 51 becomes 25%.

The 1-25 unloader valve 5141 and the 1-50 unloader valve 5142 are closed and the 1-75 unloader valve 5143 and the 1-100 unloader valve 5144 are opened, The compression capacity of the gas first stage compressor 51 becomes 50%, and the 1-25 unloader valve 5141, the 1-50 unloader valve 5142 and the 1-75 unloader valve 5143 When the 1-100 unloader valve 5144 is closed, the compression capacity of the evaporation gas first stage compressor 51 becomes 75%, and the 1-25 unloader valve 5141, When the valve 5142, the 1-75 unloader valve 5143, and the 1-100 unloader valve 5144 are both closed, it becomes 100%.

The opening and closing of the first unloader valve 514 may be via a nitrogen feeder 56, described below.

The evaporation gas second- to fifth-stage compressors 52, 53, 54, and 55 are connected to the second to fifth cylinders 523, 533, 544, and 554, respectively, which pressurize and discharge the evaporation gas flowing into the compressors 52, ).

The second to fifth cylinders 523, 533, 544 and 554 may be provided with unloading valves 524, 534, 545 and 555 for controlling the compression capacity. At least two unloading valves 5241, 524, 534, 534, 5551, 5552).

In other words, the second cylinder 523 of the evaporative gas second-stage compressor 52 may have two or more second unloader valves 524, for example, the 2-50 unloader valve 5241 and the second -100 unloader valve 5242 as shown in Fig.

When both the 2-50 unloader valve 5241 and the 2nd 100 unloader valve 5242 are opened, the compression capacity of the evaporative gas second stage compressor 52 becomes 0% The unloader valve 5241 is closed and the second -100 unloader valve 5242 is opened, the compression capacity of the evaporative gas second stage compressor 52 becomes 50%, and the second 2-50 unloader valve 5241 and the second -100 When the unloader valve 5242 is closed, it becomes 100%.

The opening and closing of the second unloader valve 524 may also be via the nitrogen feeder 56.

The contents of the second cylinder 523 and the second unloader valve 524 described in the evaporative gas second stage compressor 52 are the same in the third to fifth evaporator compressors 53, Lt; / RTI >

As described above, unlike the evaporation gas second to fifth compressors 52, 53, 54, and 55, the first unloader valve 514 includes four first unloader valves 514 to further subdivide the compression capacity So that the evaporative gas compressor 50 can be precisely controlled.

However, since the number of unloader valves is different between the first stage compressor 51 and the second to fifth stage compressors 52, 53, 54 and 55, the capacities of compression control differ from each other.

At this time, in the evaporation gas second to fifth compressors 52, 53, 54, 55, the compression capacity of the evaporative gas discharged from the first stage compressor 51 through the second to fifth bypass lines 521, 531, 541, And the second to fifth bypass valves 522, 532, 542, and 552 may be opened or closed to compensate for the difference in the compression capacity of the evaporation gas received by the second to fifth compressors 52, 53, 54, .

The evaporative gas compressor 50 further includes a nitrogen supplier 56 for supplying nitrogen to the unloader valves 514, 524, 534, 545, 555 to regulate the unloader valves 514, 524, 534, 545, 555 or for discharging nitrogen to the unloader valves 514, 524, 534, 545, 555 .

The nitrogen feeder 56 can supply nitrogen to the unloader valves 514, 524, 534, 545, 555 through the main nitrogen feed line 561.

Specifically, the nitrogen feeder 56 is connected to the first unloader valve 514 of the evaporation gas first-stage compressor 51 via the first nitrogen feed line 562 branched from the main nitrogen feed line 561, And is supplied to the second unloader valve 524 of the evaporative gas second stage compressor 52 through the second nitrogen supply line 563 branched from the main nitrogen supply line 561 and the main nitrogen supply line 561 Branched to the third unloader valve 534 of the evaporative gas third stage compressor 53 through the third nitrogen supply line 564 branched from the main nitrogen supply line 561 branched from the main nitrogen supply line 561 565 to the fourth unloader valve 545 of the fourth evaporator gas compressor 54 through the fifth nitrogen feeder line 566 branched from the main nitrogen feeder line 561, And can supply nitrogen to the first unloader valve 555 of the second unloader valve 55.

The first nitrogen supply line 562 is again connected to the 1-25 nitrogen supply line 5621, the 1-50 nitrogen supply line 5622, the 1-75 nitrogen supply line 5623, Load unloader valve 5141, the 1-50 unloader valve 5142, the 1-75 unloader valve 5143, and the 1-100 unloader valve 5144, respectively, So that nitrogen can be supplied from the nitrogen supplier 56.

In the second to fifth nitrogen supply lines 563, 564, 565, 566, the second to fifth nitrogen supply lines 5631, 5641, 5651, 5661 and the second to 100th and 5-100 nitrogen supply lines 5632, 5642, 5652,5662 are branched to the second 2-50 to 5-50 unloader valves 5241, 5334, 5544, 5551 and the second -100 to 5-100 unloader valves 5242, 5342, 5442, And can supply nitrogen from the nitrogen supplier 56.

As described above, the liquefied gas processing system 5 according to the fifth embodiment of the present invention optimally uses the available fuel provided by the ship in accordance with the situation of the ship, thereby reducing the waste of the evaporated gas, The efficient use of the energy consumed has the effect of saving the fuel cost of the vessel.

7 is a conceptual diagram of a liquefied gas processing system according to a sixth embodiment of the present invention.

7, the liquefied gas processing system 6 according to the sixth embodiment of the present invention includes a liquefied gas storage tank 10, a customer 20, a pump 30, a heat exchanger 40, A gas compressor (50), an oil storage tank (60), and an oil separator (70).

In the sixth embodiment of the present invention, each constitution is the same as the constitution except for the evaporative gas compressor 50 and the oil separator 70 in the liquefied gas processing system 3 according to the third embodiment of the present invention, But is not necessarily referring to the same configuration.

The evaporation gas compressor 50 may include bypass lines 541 and 551 for bypassing the evaporation gas from the downstream end thereof. Oil separators 71 and 72 to be described later are provided on the bypass lines 541 and 551, respectively. .

Specifically, the evaporative gas compressor (50) may include fourth and fifth bypass lines (541, 551) for bypassing from the evaporative gas fourth stage and fifth stage compressors (54, 55).

The evaporative gas compressor (50) can drive the compressors (54,55) by using oil for the evaporative gas fourth stage and fifth stage compressors (54,55), for example. When this evaporative gas compressor (50) is bypassed, the pressurized evaporative gas discharged from the evaporative gas compressor (50) is mixed with oil, and the oil gradually accumulates on the liquefied gas processing system (6).

When the oil is accumulated in the liquefied gas processing system 6, the driving line (not shown) connecting each constituent element constituting the liquefied gas processing system 6 is inflated, so that the durability is weakened and the driving efficiency is lowered . The driving line may be broken and the driving of the liquefied gas processing system 6 may be interrupted.

Therefore, in the sixth embodiment of the present invention, the bypass line 541, 551 of the fourth stage evaporating gas and the fifth stage pressure additive 54, 55 in which oil is supplied in the multi-stage evaporative gas compressor 50 It is possible to prevent oil from accumulating on the liquefied gas processing system 6 by separating the oil by installing the oil separators 71 and 72 in the liquefied gas processing system 6.

The oil separator 70 is provided on the fourth and fifth bypass lines 541 and 551 and separates the oil. Specifically, the oil separator 70 may include a fourth-stage oil separator 71 and a fifth-stage oil separator 72.

The fourth-stage oil separator 71 is provided on the fourth bypass line 541 to separate the oil, and the separated oil is supplied through the fourth-stage oil supply line 543 to the evaporation gas fourth- The evaporation gas can be supplied to the fourth cylinder 544 of the evaporation gas third stage compressor 54 and the evaporation gas can be supplied through the fourth bypass line 541 between the evaporation gas third stage compressor 53 and the evaporation gas fourth stage compressor 54 have.

The fifth-stage oil separator 72 is provided on the fifth bypass line 551 to separate the oil, and the separated oil is supplied to the fifth-stage compressor 701 through the fifth-stage oil supply line 553, The evaporative gas can be supplied to the fifth cylinder 554 of the evaporative gas fourth stage compressor 55 and the evaporative gas can be supplied through the fifth bypass line 551 between the evaporative gas fourth stage compressor 54 and the evaporative gas fifth stage compressor 55 have.

Thus, the liquefied gas processing system 6 according to the present invention can include an oil separator 70 at the downstream end of the evaporative gas compressor 50 to prevent oil buildup on the system 60, The reliability of the driving of the evaporator 60 is improved, and the load of the evaporative gas compressor 50 is reduced, thereby increasing the compression efficiency of the evaporative gas.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the same is by way of illustration and example only and is not to be construed as limiting the present invention. It is obvious that the modification and the modification are possible.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

1,2,3,4,5,6: Evaporative gas treatment system. 10: Liquefied gas storage tank
11: Evaporative gas supply line 11a: Evaporative gas parallel supply line
12: Evaporative gas branch line 13: Liquefied gas supply line
14: Oil supply line 20: Consumer
21: first customer 22: second customer
23: shaft generator 30: pump
31: auxiliary pump 32: main pump
40: Heat exchanger 50: Evaporative gas compressor
51: Evaporative gas first stage compressor 51a: Evaporative gas first parallel compressor
51b: evaporative gas second parallel compressor 511: first bypass line
512: first bypass valve 513: first cylinder
5131: Main cylinder 5132: Auxiliary cylinder
514: first unloader valve 5141: 1-25 unloader valve
5142: No. 1-50 unloader valve 5143: No. 1-75 unloader valve
5144: No. 1- 100 unloader valve 52: evaporation gas second stage compressor
521: second bypass line 522: second bypass valve
523: second cylinder 524: second unloader valve
5241: No. 2-50 unloader valve 5242: No. 2-100 unloader valve
53: Evaporative gas third stage compressor 531: Third bypass line
532: Third bypass valve 533: Third cylinder
534: Third unloader valve 5341: Third-50 unloader valve
5342: No. 3-100 unloader valve 54: evaporation gas fourth stage compressor
541: fourth bypass line 542: fourth bypass valve
543: fourth-stage oil supply line 544: fourth cylinder
545: fourth unloader valve 5451: fourth 4-50 unloader valve
5452: No. 4-100 unloader valve 55: evaporation gas fifth stage compressor
551: fifth bypass line 552: fifth bypass valve
553: fifth-stage oil supply line 554: fifth cylinder
555: fifth unloader valve 5551: fifth 5-50 unloader valve
5552: No. 5-100 unloader valve 56: nitrogen feeder
561: main nitrogen supply line 562: first nitrogen supply line
5621: No. 1-25 nitrogen supply line 5622: No. 1-50 nitrogen supply line
5623: first 75 nitrogen supply line 5624: first 1-100 nitrogen supply line
563: Second nitrogen supply line 5631: Second 2-50 nitrogen supply line
5632: 2-100 nitrogen supply line 564: third nitrogen supply line
5641: 3rd-50th nitrogen supply line 5642: 3rd-100th nitrogen supply line
565: fourth nitrogen supply line 5651: fourth 4-50 nitrogen supply line
5652: 4-100 nitrogen supply line 566: fifth nitrogen supply line
5661: the 5-50 nitrogen supply line 5662: the 5-100 nitrogen supply line
60: Oil storage tank 61: Oil supply valve
70: oil separator 71: fourth-stage oil separator
72: Stage 5 oil separator a: MEGI gas consumption
b: MEGI + SG gas consumption c: Laden evaporation gas emission amount

Claims (13)

An evaporation gas supply line connecting the high-pressure gas injection engine in the liquefied gas storage tank to supply the evaporation gas;
An evaporative gas compressor provided on the evaporative gas supply line for multi-stepping the evaporative gas;
An evaporation gas branch line for supplying an evaporation gas pressurized by at least a part of the evaporation gas compressor to a low pressure consumer site;
A shaft generator driven by the high-pressure gas injection engine;
A liquefied gas supply line connecting the high-pressure gas injection engine in the liquefied gas storage tank to supply liquefied gas; And
An oil supply line connecting the high-pressure gas injection engine in an oil storage tank,
In the first mode in which the ship loads or unloads the liquefied gas,
Supplying only the evaporated gas of the liquefied gas storage tank to the low-pressure consumer,
In a second mode in which the ship is operated at a predetermined speed or lower,
Supplying the vaporized gas of the liquefied gas storage tank to the low-pressure consumer and the high-pressure gas injection engine,
In the third mode in which the ship is operated at the predetermined speed,
Supplying a vaporized gas of the liquefied gas storage tank to the high-pressure gas injection engine,
In the fourth mode in which the ship is operated at the maximum speed,
Supplying a vaporized gas and a liquefied gas from the liquefied gas storage tank to the high-pressure gas injection engine and supplying oil from the oil storage tank to the high-pressure gas injection engine,
In the third and fourth modes, the high-pressure gas-
And is driven together with the shaft generator. 2. The method of claim 1,
Mode < RTI ID = 0.0 > 2a < / RTI >
And a second mode in which the ship is operated at the predetermined speed. 3. The method according to claim 2,
Is within a predetermined range including a half speed of the maximum speed of the ship. 3. The method according to claim 2,
And the average speed of the ship is within a predetermined range including the average speed of the ship. The system of claim 2, wherein the low-
DFDE, remelting device or GCU,
And the high-pressure gas injection engine in the second mode,
And the shaft generator is also driven together. The method according to claim 1,
An auxiliary pump provided in the liquefied gas supply line and supplying the liquefied gas to the high-pressure gas injection engine;
A main pump for supplying liquefied gas from the auxiliary pump and compressing the liquefied gas at a high pressure; And
Further comprising a heat exchanger for supplying and heating the liquefied gas from the main pump. 6. The apparatus of claim 5, wherein the shaft generator comprises:
Pressure gas injection engine is connected to the high-pressure gas injection engine and is driven using at least a part of the power generated in the high-pressure gas injection engine. The compressor according to claim 1,
A multi-stage compressor comprising five stages,
Wherein the evaporation gas branch line comprises:
And branches between the second and third stages of the evaporative gas compressor. 6. The method of claim 5, wherein in the first mode,
And the DFDE is preferentially driven. 10. The method of claim 9, wherein when the supply amount of the evaporation gas is larger than the required amount of the DFDE,
Liquefier, and the GCU are sequentially operated. 6. The method of claim 5, wherein in the 2a mode,
The high-pressure gas injection engine and the DFDE are simultaneously driven,
When the supply amount of the evaporation gas is larger than the required amount of the DFDE,
Liquefier, and the GCU are sequentially operated. 6. The method according to claim 5, wherein in the second mode,
The high-pressure gas injection engine, the shaft generator, and the DFDE,
When the supply amount of the evaporation gas is larger than the sum of the evaporation gas required amount of the high-pressure gas injection engine and the evaporation gas required amount of the DFDE,
And the liquefaction device is driven. 6. The method of claim 5, wherein in the third mode,
And drives only the high-pressure gas injection engine and the shaft generator.

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