KR20180055245A - Gas Treatment System and Vessel having same - Google Patents

Abstract

According to an embodiment of the present invention, a gas treatment system comprises: a pump supplying liquefied gas stored in a liquefied gas storage tank to a propulsion engine; a boil-off gas compressor compressing boil-off gas generated in the liquefied gas storage tank; a heat exchanger heat exchanging the liquefied gas supplied from the pump with the boil-off gas supplied from the boil-off gas compressor; and a boil-off gas circulation line formed to enable the boil-off gas generated in the liquefied gas storage tank to return to the liquefied gas storage tank, and provided with the heat exchanger. At least a portion of the boil-off gas is re-liquefied in the heat exchanger to return to the liquefied gas storage tank by the boil-off gas circulation line without being heat exchanged by additional refrigerant.

Description

TECHNICAL FIELD [0001] The present invention relates to a gas treatment system and a vessel including the same,

The present invention relates to a gas treatment system and a vessel including the same.

Liquefied natural gas (Liquefied natural gas), Liquefied petroleum gas (Liquefied petroleum gas) and other liquefied gas are widely used in place of gasoline or diesel in recent technology development.

Liquefied natural gas is a liquefied natural gas obtained by refining natural gas collected from a gas field. It is a colorless and transparent liquid with almost no pollutants and high calorific value. It is an excellent fuel. On the other hand, liquefied petroleum gas is a liquid fuel made by compressing gas containing propane (C3H8) and butane (C4H10), which come from oil in oil field, at room temperature. Liquefied petroleum gas, like liquefied natural gas, is colorless and odorless and is widely used as fuel for household, business, industrial, and automotive use.

Such liquefied gas is stored in a liquefied gas storage tank installed on the ground or stored in a liquefied gas storage tank provided in a ship which is a means of transporting the ocean. The liquefied natural gas is liquefied to a volume of 1/600 The liquefaction of liquefied petroleum gas has the advantage of reducing the volume of propane to 1/260 and the content of butane to 1/230, resulting in high storage efficiency. The temperature and pressure necessary for driving the engine using such liquefied gas as fuel may be different from the state of the liquefied gas stored in the tank.

In addition, when LNG is stored in a liquid state, some LNG is vaporized and boil off gas (BOG) is generated as heat penetration occurs in the tank. Such evaporation gas may cause problems in a liquefied gas processing system. In order to solve the problem by discharging the evaporation gas to the outside (in the past, the evaporation gas was simply discharged to the outside in order to lower the tank pressure by lowering the tank pressure), the problem was solved. However, .

 In recent years, researches and developments have been actively conducted on utilization methods such as recycling the generated evaporated gas through a liquefied gas, liquefying it, and supplying it to the engine as a technique for efficiently processing the evaporated gas.

The present invention has been made to improve the prior art, and an object of the present invention is to provide a gas processing system and a ship including the same, which effectively supply liquefied gas and / or evaporated gas from a liquefied gas storage tank to a customer .

A gas treatment system according to the present invention comprises a pump for supplying liquefied gas stored in a liquefied gas storage tank to a propulsion engine; An evaporative gas compressor for compressing the evaporated gas generated in the liquefied gas storage tank; A heat exchanger for exchanging heat between the liquefied gas supplied from the pump and the evaporation gas supplied from the evaporation gas compressor; And an evaporated gas circulation line formed to return to the liquefied gas storage tank again the evaporated gas generated in the liquefied gas storage tank, wherein the evaporated gas is at least partially re-liquefied in the heat exchanger, And is returned to the liquefied gas storage tank by the evaporation gas circulation line without heat exchange by a separate refrigerant.

The controller may further include a control unit for controlling the flow of the evaporated gas heat-exchanged in the heat exchanger according to the load of the propulsion engine to re-liquefy the evaporated gas supplied from the evaporative gas compressor without a re-liquefier having another refrigerant .

Specifically, when the load of the propulsion engine is equal to or greater than a preset load, the control unit controls the evaporator so that evaporated gas completely re-liquefied in the heat exchanger is supplied to the liquefied gas storage tank, , It is possible to control both the liquid phase and the vapor phase of the partially re-liquefied evaporated gas in the heat exchanger to be supplied to the liquefied gas storage tank.

Specifically, the load may be such that the linear velocity is 17 to 18 knots (Knot).

Specifically, the gas-liquid separator may further include a gas-liquid separator for receiving the heat-exchanged vapor gas from the heat exchanger and separating the gas-liquid and liquid.

Specifically, a re-liquefied return line connecting the lower side of the gas-liquid separator and the liquefied gas storage tank; A refill return valve provided on the refill return line; A flash gas supply line connecting the upper side of the gas-liquid separator and the liquefied gas storage tank; And a flash gas supply valve provided on the flash gas supply line, wherein the evaporation gas regression line includes the refill return line and the flash gas return line, When the temperature of the liquefied gas storage tank is higher than the predetermined load, opening of the re-liquefaction return valve is opened and the opening of the flash gas supply valve is closed, so that evaporated gas completely re-liquefied in the heat exchanger is supplied to the liquefied gas storage tank, Wherein when the load of the propulsion engine is lower than a preset load, opening of the re-liquefied return valve and opening of the flash gas supply valve are opened, so that both the liquid phase and the vapor phase of the partially re- To be supplied to the storage tank.

The controller may further include a control unit for controlling the flow of the evaporative gas flowing into the heat exchanger depending on the load of the propulsion engine and re-liquefying the evaporative gas supplied from the evaporative gas compressor without a re-liquefier having another refrigerant have.

Specifically, an evaporative gas liquefaction line connecting the liquefied gas storage tank and the heat exchanger and having the evaporative gas compressor; And an evaporative gas addition supply line connecting the liquefied gas storage tank and the evaporation gas consumption source and supplying the evaporation gas generated in the liquefied gas storage tank to the evaporation gas consumption source without a compression means, The evaporation gas liquefaction line, and when the load of the propulsion engine is equal to or higher than a predetermined load, the evaporation gas generated in the liquefied gas storage tank flows through the evaporation gas liquefaction line to the evaporation gas compressor And controls at least a part of the evaporated gas generated in the liquefied gas storage tank to be supplied to the evaporative gas compressor through the evaporated gas liquefaction line when the load of the propulsion engine is less than a preset load, And the remainder of the evaporated gas generated in the liquefied gas storage tank flows through the additional evaporation gas supply line It can be controlled so as to be supplied to the boil-off gas sobicheo.

Specifically, the evaporation gas first supply valve provided on the evaporation gas liquefaction line; And an evaporation gas second supply valve provided on the evaporation gas addition supply line, wherein, when the load of the propulsion engine is equal to or higher than a preset load, the second control unit controls the opening degree of the evaporation gas first supply valve Closing the opening of the evaporation gas second supply valve to control the evaporation gas generated in the liquefied gas storage tank to be supplied to the evaporation gas liquefaction line in its entirety, and when the load of the propulsion engine is less than a preset load , The opening degree of the evaporation gas first supply valve is decreased and the opening degree of the evaporation gas second supply valve is opened so that at least a part of the evaporation gas generated in the liquefied gas storage tank is supplied to the evaporation gas liquefaction line , And the rest is supplied to the evaporation gas addition supply line.

Specifically, the load may be such that the linear velocity is 17 to 18 knots (Knot).

A liquefied gas supply line connecting the liquefied gas storage tank and the demander; An evaporation gas supply line connecting the liquefied gas storage tank and the evaporation gas consumption site; And an evaporation gas liquefaction line branched from the evaporation gas compressor and the evaporation gas consuming place on the evaporation gas supply line and connected to the heat exchanger, wherein the evaporation gas regeneration line comprises at least a part of the evaporation gas supply line And the evaporation gas liquefaction line may be reconnected to the liquefied gas storage tank without the gas-liquid separator so that the fully re-liquefied evaporated gas in the heat exchanger is returned to the liquefied gas storage tank.

Specifically, it may be a vessel characterized by including the gas treatment system.

The gas treatment system and the vessel including the gas treatment system according to the present invention have an effect of effectively supplying liquefied gas and / or evaporated gas from a liquefied gas storage tank to a customer, thereby enhancing system stability and reliability.

1 is a conceptual diagram of a conventional gas processing system.
2 is a conceptual diagram of a gas processing system according to an embodiment of the present invention.
3 is a conceptual diagram of a gas processing system according to another embodiment of the present invention.

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, the liquefied gas may be LPG, LNG, or ethane, and may be, for example, LNG (Liquefied Natural Gas), and the evaporation gas may refer to BOG (Boil Off Gas) such as natural vaporized LNG.

The liquefied gas can be referred to irrespective of the state change, such as liquid state, gas state, mixed state of liquid and gas, supercooled state, supercritical state, and the like. Further, it is apparent that the present invention is not limited to the liquefied gas to be treated, but may be a liquefied gas processing system and / or an evaporative gas processing system, and the systems of the following drawings may be applied to each other. In addition, the mixed fluid described below may be a mixed vaporized gas or a fluid containing at least a part of the liquid phase.

Further, the embodiments of the gas treatment system 2 of the present invention may be configured in combination with each other, and the addition of the respective structures may be made to be an intersection with each other. The gas processing system 2 according to an embodiment of the present invention may be mounted on a hull (not shown), and a vessel (not shown) may be a ship such as an LNG carrier, a container carrier, It is not limited.

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 conventional gas processing system.

1, a conventional gas processing system 1 includes a liquefied gas storage tank 10, a boosting pump 20, a high-pressure pump 21, a vaporizer 30, an evaporative gas compressor 40, And includes a propulsion engine 51 and a vapor gas consuming place 52.

The conventional gas processing system 1 is divided into a liquefied gas processing unit on the liquefied gas supply line L1 and an evaporative gas processing unit on the evaporated gas supply line L2.

The liquefied gas processing apparatus supplies the liquefied gas stored in the liquefied gas storage tank 10 to the high pressure pump 21 through the boosting pump 20 and the liquefied gas supplied from the boosting pump 20 through the high pressure pump 21, The gas is supplied to the vaporizer 30 through the high pressure pump 21 through the vaporizer 30 and is supplied to the propulsion engine 51. [

The evaporation gas processing apparatus compresses the evaporation gas generated in the liquefied gas storage tank 10 by the evaporation gas compressor 40 and supplies it to the evaporation gas consuming unit 52. Here, the evaporation gas consumption site 52 may be a boiler 52a or a low-pressure gas injection engine 52b (power generation engine).

Conventional gas processing system 1 processes liquefied gas or vaporized gas using the above-described liquefied gas processing apparatus and vaporized gas processing apparatus, but the consumption of the vaporized gas is not so much compared to the amount of the generated vaporized gas, Has always been a problem.

Accordingly, the gas processing system 2 according to the embodiment of the present invention has solved the above problems remarkably and will be described in detail below.

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

2, the gas processing system 2 according to an embodiment of the present invention includes a liquefied gas storage tank 10, a boosting pump 20, a high-pressure pump 21, a vaporizer 30, A compressor 40, a preheater 41, a propulsion engine 51, an evaporation gas consuming unit 52, a heat exchanger 60, a gas-liquid separator 61, a heater 70 and a first control unit 81.

Hereinafter, a gas processing system 2 according to an embodiment of the present invention will be described with reference to FIG.

Prior to describing the individual configurations of the gas processing system 2 according to the embodiment of the present invention, the basic flow paths for organically connecting the individual structures will be described. Here, the passage is a passage through which the fluid flows, and may be a line. However, the present invention is not limited thereto.

In the embodiment of the present invention, the liquefied gas supply line L1, the evaporation gas supply line L2, the evaporation gas liquefaction line L3, the flash gas supply line L4, the re-liquefaction return line L5, And may further include a supply line L6. Valves (not shown) capable of adjusting the opening degree may be provided in each line, and the supply amount of the evaporation gas may be controlled according to the opening degree of each valve.

The liquefied gas supply line L1 connects the liquefied gas storage tank 10 and the propulsion engine 51 and is provided with a feeding pump 20, a heat exchanger 60, a high-pressure pump 21 and a vaporizer 30 So that the liquefied gas stored in the liquefied gas storage tank 10 can be supplied to the propulsion engine 51.

The evaporation gas supply line L2 connects the liquefied gas storage tank 10 and the evaporation gas consumption site 52 and is provided with an evaporation gas compressor 40 and a preheater 41 so as to be connected to the liquefied gas storage tank 10 And the generated evaporated gas can be supplied to the evaporated gas consumption site 52.

The evaporation gas liquefaction line L3 branches between the evaporation gas compressor 40 and the evaporation gas consuming place 52 on the evaporation gas supply line L2 and is connected to the gas-liquid separator 61 and has a heat exchanger 60 So that at least a part of the evaporated gas generated in the liquefied gas storage tank 10 can be re-liquefied and supplied to the gas-liquid separator 61.

The flash gas supply line L4 connects the gas-liquid separator 61 and the liquefied gas storage tank 10 and can supply the gaseous flash gas remaining in the gas-liquid separator 61 to the liquefied gas storage tank 10 .

A flash gas supply valve 812 is provided on the flash gas supply line L4 and can be connected to the first control unit 81 by wire or wireless. The flash gas supply valve 812 is connected to the first control unit 81 The flow rate of the flash gas supplied from the gas-liquid separator 61 to the liquefied gas storage tank 10 can be adjusted.

The re-liquefaction return line L5 connects the gas-liquid separator 61 and the liquefied gas storage tank 10 and can supply the re-liquefied evaporated gas separated from the gas-liquid separator 61 to the liquefied gas storage tank 10 have.

A re-liquefaction return valve 811 is provided on the re-liquefaction return line L5 and can be connected to the first control unit 81 by wire or wireless. The re-liquefaction return valve 811 is connected to the first control unit 81 Liquid separator 61 to regulate the flow rate of the re-liquefied evaporative gas supplied to the liquefied gas storage tank 10 in accordance with the opening degree adjusting command of the gas-liquid separator 61.

The evaporation gas additional supply line L6 connects the liquefied gas storage tank 10 and the evaporation gas consumption site 52 and preferably connects the liquefied gas storage tank 10 and the boiler 52a.

The internal pressure of the liquefied gas storage tank 10 is used so that at least a part of the evaporated gas generated in the liquefied gas storage tank 10 is supplied to the evaporation gas addition supply line L6 without using any additional pressurizing device or compression device And can be supplied to the boiler 52a. At this time, the boiler 52a does not require a high pressure to burn the evaporation gas, and the combustion can be performed when the pressure of the evaporation gas is 1 to 1.06 bar.

Hereinafter, the individual structures that are organically formed by the above-described respective lines L1 to L6 to implement the gas processing system 2 will be described.

The liquefied gas storage tank 10 stores a liquefied gas or an evaporated gas to be supplied to the propulsion engine 51 or the evaporation gas consuming unit 52. The liquefied gas storage tank 10 must store the liquefied gas in a liquid state, in which case the liquefied gas storage tank 10 may have the form of a pressure tank.

Here, the liquefied gas storage tank 10 is disposed inside the hull, and four liquefied gas storage tanks 10 may be formed in front of the engine room (not shown). In addition, the liquefied gas storage tank 10 is not particularly limited to various types such as a membrane-type tank or an independent tank, for example.

A boosting pump 20 is provided on the liquefied gas supply line L1 and pressurizes the liquefied gas in the liquefied gas storage tank 10 and supplies it to the propulsion engine 51. [

The boosting pump 20 may be provided on the liquefied gas supply line L 1 between the liquefied gas storage tank 10 and the high pressure pump 21 so that a sufficient amount of liquefied gas is supplied to the high pressure pump 21. Thereby preventing cavitation of the high-pressure pump 21.

Also, the boosting pump 20 can pressurize the liquefied gas from the liquefied gas storage tank 10 to several to several tens of bars, and the liquefied gas through the boosting pump 20 is pressurized to 1 to 25 bar .

The liquefied gas stored in the liquefied gas storage tank 10 is in a liquid state. At this time, the boosting pump 20 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 boosting pump 20 may still be in a liquid state.

The high pressure pump 21 is provided on the liquefied gas supply line L 1 and pressurizes the liquefied gas supplied from the boosting pump 20 and supplies the liquefied gas to the propulsion engine 51.

The high pressure pump 21 may be provided on the liquefied gas supply line L1 between the boosting pump 20 and the vaporizer 30 and pressurizes the liquefied gas discharged from the liquefied gas storage tank 10 to high pressure , And to be supplied to the propulsion engine (51).

The liquefied gas is discharged from the liquefied gas storage tank 10 at a pressure of about 10 bar and is then primarily pressurized by the boosting pump 20. The high pressure pump 21 is driven by the boosting pump 20 The liquefied gas is secondarily pressurized and supplied to the vaporizer 30. [

At this time, the high-pressure pump 21 pressurizes the liquefied gas to a pressure required by the propulsion engine 51, for example, 200 bar to 400 bar and supplies it to the propulsion engine 51 so that the propulsion engine 51 can be powered Can be produced.

The high-pressure pump 21 pressurizes the liquid-state liquefied gas discharged from the boosting pump 20 at a high pressure, and changes the phase of the liquefied gas to a supercritical state having a higher temperature and a higher pressure than the critical point . At this time, the temperature of the liquefied gas in the supercritical state may be minus 20 degrees Celsius, which is relatively higher than the critical temperature.

Or the high-pressure pump 21 can pressurize the liquefied gas in the liquid state to a super-cooled liquid state by pressurizing it with 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 high-pressure pump 21 pressurizes the liquid-state liquefied gas discharged from the boosting pump 20 at a high pressure of 200 to 400 bar, and the liquefied gas is cooled to a temperature 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 vaporizer 30 is provided on the liquefied gas supply line L1 between the propulsion engine 51 and the high pressure pump 21 and exchanges the liquefied gas supplied from the high pressure pump 21.

The vaporizer 30 heat-exchanges the liquefied gas in the subcooled liquid state or the supercritical state while maintaining the pressure of 200 bar to 400 bar, which is the pressure discharged from the high-pressure pump 21, and converts the liquefied gas into supercritical liquefied gas at 30 to 60 degrees Can be supplied to the engine (51).

The evaporative gas compressor (40) is provided on the evaporative gas supply line (L2) and can pressurize the evaporative gas generated in the liquefied gas storage tank (10). The evaporation gas compressor 40 may supply the evaporation gas to the evaporation gas consuming unit 52 by pressurizing the evaporation gas generated in the liquefied gas storage tank 10 at a pressure of about 1 bar and a pressure of 8 bar to 10 bar.

At this time, the evaporation gas consumption source 52 may include a boiler 52a and a low-pressure gas injection engine 52b, and the evaporation gas compressor 40 may be connected to the boiler 52a and the low-pressure gas injection engine 52b So that the evaporation gas can be supplied.

The plurality of evaporation gas compressors (40) can pressurize the evaporation gas at multiple stages. For example, the evaporation gas compressor 40 may include two to three pistons (not shown) so that the evaporation gas may be pressurized from the second stage to the third stage.

Between the plurality of evaporative gas compressors 40, an evaporative gas cooler (not shown) may be provided. When the evaporation gas is pressurized by the evaporation gas compressor 40, the temperature can also be raised in accordance with the pressure increase. Therefore, the present embodiment can lower the temperature of the evaporation gas again by using the evaporation gas cooler. The evaporative gas cooler may be installed in the same number as the evaporative gas compressor 40, and each evaporative gas cooler may be provided downstream of each evaporative gas compressor 40.

At this time, the evaporated gas discharged from the evaporating gas compressor (40) located at the end based on the flow of the evaporating gas may have a pressure of 8 to 10 bar.

The preheater 41 is provided between the evaporative gas compressor 40 on the evaporative gas supply line L2 and the liquefied gas storage tank 10 so as to preheat the evaporated gas supplied to the evaporative gas compressor 40. [ Here, the preheater 41 can use steam as a heat source.

The evaporative gas compressor (40) according to the embodiment of the present invention may be, for example, a room temperature compressor. Of course, the present invention is not limited to this and may be a cryogenic compressor, but it may be used as a compressor for room temperature when the pre-heater 41 is installed.

The room temperature compressor requires that the temperature of the incoming evaporating gas be approximately minus 40 degrees to minus 20 degrees and the temperature of the evaporating gas generated in the liquefied gas storage tank 10 has a temperature of approximately minus 100 degrees and very low .

Therefore, when the evaporative gas compressor 40 according to the embodiment of the present invention is a room-temperature compressor, the evaporation gas of about -10 ° C. generated in the liquefied gas storage tank 10 through the preheater 41 is cooled to about minus 40.degree. 20 < / RTI > degrees to the evaporative gas compressor (40).

The propulsion engine 51 may be a high pressure engine and may be a high pressure fuel injection engine (for example, a MEGI engine) and may be supplied with liquefied gas stored in the liquefied gas storage tank 10 through the liquefied gas supply line L1 Thereby generating thrust.

The propulsion engine 51 may be a high pressure gas of about 300 bar, and in the case of a turbine, it may be a gas turbine, a steam turbine, and a steam turbine (HRSG) using waste heat. Turbines can be used to produce power and can be used to generate hull power by being connected to drive shafts that propel propellers directly.

The propulsion engine 51 may be a dual fuel engine in which dual fuel is available. A dual fuel engine is typically a two-stroke engine 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.

The propulsion engine 51 may include a sensor (not shown) to transmit the load information of the propulsion engine 51 to the first controller 81 in a wireless manner.

The evaporation gas consuming place 52 may include a boiler 52a, a low pressure gas injection engine 52b, a turbine (not shown), and a GCU (not shown) But is not limited thereto.

The evaporation gas consumer 52 is a consumer using a low-pressure evaporation gas compressed by the evaporation gas compressor 40 in a two-stage or three-stage compression to about 7 to 10 bar, and is preferably used as a boiler 52a, Engine (DFDE engine) 52b.

The boiler 52a is connected to the additional gas supply line L6 to supply and discharge the evaporation gas of 1 to 1.06 bar. The boiler 52a is connected to the evaporation gas supply line L2 to supply the evaporation gas of 8 to 10 bar It can receive and consume.

The low-pressure gas injection engine 52b is connected to the evaporation gas supply line L2 and can supply and discharge evaporation gas of 8 to 10 bar.

The low pressure gas injection engine 52b may be a dual fuel engine in which a dual fuel can be used so that the liquefied gas (vaporized) as well as the oil can be used as the fuel, but the liquefied gas (vaporized) Fueled engine in which liquefied gas (vaporized) or oil is selectively supplied. This is to prevent the mixture of two substances having different combustion temperatures from being mixed, thereby preventing the efficiency of the low-pressure gas injection engine 52b from deteriorating.

The heat exchanger 60 is provided between the booster pump 20 and the high-pressure pump 21 on the liquefied gas supply line L1 and is provided between the evaporative gas compressor 40 on the evaporative gas liquefaction line L3 and the gas-liquid separator 61 As shown in FIG.

The heat exchanger 60 can receive heat of the liquefied gas from the liquefied gas supply line L1 and exchange heat between the evaporated gas supplied from the evaporated gas liquefaction line L3 and heat the evaporated gas through the cold heat of the liquefied gas It can be liquefied.

Here, the heat exchanger 60 can completely re-liquefy the supplied evaporated gas when the load of the propulsion engine 51 is such that the predetermined load, that is, the speed of the ship is approximately 17 knots or more, In the case where the load of the engine 51 is such that the speed of the ship is less than approximately 17 knots, it is possible to partially re-liquefy the part where the supplied evaporated gas is at least partially re-liquefied. The details of this are described in the first control section 81.

The heat exchanger (60) can supply the re-liquefied evaporated gas to the gas-liquid separator (61) and can supply the liquefied gas heat-exchanged with the evaporated gas to the high-pressure pump (21).

The gas-liquid separator 61 is connected to the evaporation gas liquefaction line L3 to be supplied with the re-liquefied evaporated gas from the heat exchanger 30, and supplies the supplied re-liquefied evaporated gas to the gas- .

Liquid separator 61 is connected to the upper side of the flash gas supply line L4 to supply the vapor phase to the liquefied gas storage tank 10 and the re-liquefaction return line L5 is connected to the lower side, Can be supplied to the tank (10).

At this time, the gas phase is flash gas and the temperature is approximately -162.3 degrees. Accordingly, since the temperature of the natural evaporation gas is much lower than the temperature of minus 100 degrees, and the amount of heat contained is small, when the liquefied gas is returned to the liquefied gas storage tank 10, You can give.

The heater 70 is provided between the liquefied gas storage tank 10 and the boiler 52a on the additional gas supply line L6 and supplies the evaporated gas generated in the liquefied gas storage tank 10 to the boiler 52a The temperature can be raised to the required temperature and supplied.

The heater (70) can use steam as a heat source and can share a heat source with the preheater (41).

The first control unit 81 controls the flow of the evaporated gas heat-exchanged in the heat exchanger 60 according to the load of the propulsion engine 51 and supplies the evaporated gas from the evaporative gas compressor 40 without a liquefaction device having a separate refrigerant Thereby re-liquefying the evaporated gas.

The re-liquefaction rate of the evaporated gas supplied to the heat exchanger 60 is proportional to the amount of the liquefied gas supplied to the heat exchanger 60. [ Accordingly, when the load of the propulsion engine 51 is high, the amount of the liquefied gas supplied to the propulsion engine 51 is increased correspondingly (the liquefied gas supply line L1 is required to supply the liquefied gas to the propulsion engine 51) If the load of the propulsion engine 51 is low, the amount of the liquefied gas supplied to the propulsion engine 51 is increased by the amount of the liquefied gas supplied to the heat exchanger 60 The re-liquefaction rate of the evaporated gas supplied to the heat exchanger 60 becomes low.

According to the study of the present applicant, when the load of the propulsion engine 51 reaches a load of 17 knots or 18 knots, the amount of the liquefied gas supplied to the propulsion engine 51 can be completely re- .

Accordingly, in the embodiment of the present invention, when the load of the propulsion engine 51 becomes smaller than the load in the case where the load of the propulsion engine 51 becomes 17 knots or 18 knots at the line speed through the first control unit 81, By liquefying the liquefied gas storage tank 10 with pressure, it is possible to realize liquefaction of the evaporated gas without using a re-liquefier having another refrigerant.

Specifically, when the load of the propulsion engine 51 is equal to or higher than the preset load, the first control unit 81 controls the evaporator gas to be completely re-liquefied in the heat exchanger 60 to be supplied to the liquefied gas storage tank 10 , And when the load of the propulsion engine 51 is less than the preset load, the liquid and vapor phases of the partially re-liquefied evaporated gas in the heat exchanger 60 can be controlled to be supplied to the liquefied gas storage tank 10. The load is such that the line speed is 17 to 18 knots.

The first control unit 81 is connected to the re-liquefaction return valve 811, the flash gas supply valve 812 and the propulsion engine 51 in a wired or wireless manner to receive the load information from the propulsion engine 51, The liquefaction return valve 811 and the flash gas supply valve 812 may transmit opening adjustment commands.

The first control unit 81 opens the opening of the re-liquefaction return valve 811 and closes the opening of the flash gas supply valve 812 when the load of the propulsion engine 51 is equal to or more than the predetermined load, Liquefied return valve 811 and the flash gas is supplied to the liquefied gas storage tank 10 when the load of the propulsion engine 51 is less than the preset load, The opening of the supply valve 812 is opened so that both the liquid phase and the vapor phase of the partially re-liquefied evaporated gas in the heat exchanger 60 can be controlled to be supplied to the liquefied gas storage tank 10.

As described above, the gas processing system 2 according to the embodiment of the present invention is a system in which the liquefied gas supplied from the liquefied gas storage tank 10 to the propulsion engine 51 and the evaporated gas generated from the liquefied gas storage tank 10 It is possible to completely treat the evaporation gas without optimizing the heat exchange and without a re-liquefying device having a separate refrigerant, and thus the processing of the evaporation gas can be very effectively implemented.

Ultimately the gas treatment system 2 according to the present invention effectively supplies the liquefied and / or vaporized gas from the liquefied gas storage tank 10 to the propulsion engine 51 or to the vaporized gas consumer 52, Thereby improving reliability.

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

3, the gas processing system 2 according to another embodiment of the present invention includes a liquefied gas storage tank 10, a boosting pump 20, a high-pressure pump 21, a vaporizer 30, A compressor 40, a preheater 41, a propulsion engine 51, an evaporation gas consuming unit 52, a heat exchanger 60, a heater 70 and a second control unit 82.

In the embodiment of the present invention, except for the second control unit 82, the same reference numerals are used for the respective constructions in the gas processing system 2 according to the embodiment of the present invention described with reference to FIG. 2 , It does not necessarily refer to the same configuration.

Further, in the embodiment of the present invention, there is a difference in that the gas-liquid separator 61 is omitted in the gas processing system 2 according to the embodiment of the present invention described with reference to FIG. 2, L4 and the re-liquefaction return line L5 are also omitted.

Hereinafter, a gas processing system 2 according to another embodiment of the present invention will be described with reference to FIG. 3, and the second control unit 82 will be mainly described.

In the embodiment of the present invention, the evaporation gas first supply valve 821 and the evaporation gas second supply valve 822 may be further included.

The evaporation gas first supply valve 821 is provided on the evaporation gas supply line L1 to control the flow rate of the evaporation gas supplied from the liquefied gas storage tank 10 to the evaporation gas compressor 40, The second gas supply valve 822 is provided on the additional gas supply line L6 to control the flow rate of the evaporative gas supplied from the liquefied gas storage tank 10 to the evaporative gas consuming unit 52.

At this time, the evaporation gas first and second supply valves 821 and 822 are all connected to the second control unit 82 by wire or wireless, and can receive the opening control command from the second control unit 82.

The second control unit 82 controls the flow of the evaporative gas flowing into the heat exchanger 60 according to the load of the propulsion engine 51 to supply the evaporative gas from the evaporative gas compressor 40 without a liquefaction device having a separate refrigerant It is possible to re-liquefy the evaporated gas.

According to the description of the gas processing system 2 of the present invention described above with reference to Fig. 2 (the first control unit 81), the load of the propulsion engine 51 when the load of the propulsion engine 51 becomes 17 knots or 18 knots It has been found that the re-injection of the evaporated gas can be completely performed by the amount of the liquefied gas supplied to the propulsion engine 51. Accordingly, in the embodiment of the present invention, the flow rate of the evaporation gas supplied to the heat exchanger 60 is controlled through the second control unit 82, and the flow rate of the liquefied gas supplied from the heat exchanger 60 is relatively reduced By reducing the flow rate of the evaporation gas supplied to the heat exchanger (60), complete re-liquefaction in the heat exchanger (60) can be realized.

More specifically, when the load of the propulsion engine 51 is equal to or higher than the predetermined load, the second control unit 82 controls the second control unit 82 so that the evaporated gas generated in the liquefied gas storage tank 10 flows through the evaporated gas liquefaction line L3, And at least a part of the evaporation gas generated in the liquefied gas storage tank 10 is evaporated through the evaporation gas liquefaction line L3 when the load of the propulsion engine 51 is less than the predetermined load, Gas compressor 40 so that the remainder of the evaporated gas generated in the liquefied gas storage tank 10 is supplied to the evaporation gas consuming unit 52 through the evaporated-gas addition supply line L6.

The second control section 82 is connected to the evaporation gas first supply valve 821, the evaporation gas second supply valve 822 and the propulsion engine 51 in a wired or wireless manner, And deliver the opening regulation command to the evaporation gas first supply valve 821 and the evaporation gas second supply valve 822. [

The second control unit 82 opens the opening of the evaporation gas first supply valve 821 and closes the opening of the evaporation gas second supply valve 822 when the load of the propulsion engine 51 is equal to or more than the pre- So that the evaporation gas generated in the liquefied gas storage tank 10 is supplied to the evaporation gas supply line L2 (preferably the evaporation gas liquefaction line L3) The opening degree of the evaporation gas first supply valve 821 is decreased and the opening degree of the evaporation gas second supply valve 822 is opened so that at least a part of the evaporation gas generated in the liquefied gas storage tank 10 To be supplied to the evaporation gas supply line L2 (preferably, the evaporation gas liquefaction line L3), and the rest to be supplied to the evaporation gas addition supply line L6. The extent to which the second control unit 82 reduces the opening degree of the first evaporation gas supply valve 821 is determined by the amount of evaporation gas supplied to the heat exchanger 60 by heat exchange with the liquefied gas, The flow rate of the evaporation gas supplied to the unit 60 can be reduced.

At this time, a three-way valve (not shown) is provided at a point where the evaporation gas supply line L2 and the evaporation gas liquefaction line L3 are branched, and the evaporation gas compressor 40 is controlled by the second control unit 82 It is possible to control the supply of the evaporated gas to be discharged to the evaporation gas consuming unit 52 or the supply to the heat exchanger 60.

As described above, only the amount of the evaporative gas that can be completely re-liquefied by the heat exchanger 60 is supplied to the heat exchanger 60 according to the load of the propulsion engine 51 through the second control unit 82 of the present invention, It is possible to realize complete re-liquefaction without a re-liquefier having a separate refrigerant, thereby omitting the gas-liquid separator 61.

Therefore, in the embodiment of the present invention, the evaporation gas liquefaction line L3 can be directly connected to the liquefied gas storage tank 10. [

As described above, the gas processing system 2 according to the embodiment of the present invention is a system in which the liquefied gas supplied from the liquefied gas storage tank 10 to the propulsion engine 51 and the evaporated gas generated from the liquefied gas storage tank 10 It is possible to realize complete re-liquefaction of the evaporated gas without the re-liquefying apparatus having a separate refrigerant by optimizing the heat exchange, and thus the processing of the evaporated gas can be realized very effectively.

Ultimately the gas treatment system 2 according to the present invention effectively supplies the liquefied and / or vaporized gas from the liquefied gas storage tank 10 to the propulsion engine 51 or to the vaporized gas consumer 52, Thereby improving reliability.

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: conventional gas treatment system 2: gas treatment system of the present invention
10: Liquefied gas storage tank 20: Boosting pump
21: high pressure pump 30: vaporizer
40: Evaporative gas compressor 41: Preheater
51: Propulsion engine 52: Evaporation gas consumer
52a: boiler 52b: low pressure gas injection engine
60: heat exchanger 61: gas-liquid separator
70: Heater 81:
811: Re-liquefied return valve 812: Flash gas supply valve
82: second control section 821: evaporation gas first supply valve
822: Evaporative gas second supply valve
L1: liquefied gas supply line L2: evaporation gas supply line
L3: Evaporative gas liquefaction line L4: Flash gas supply line
L5: Re-liquefaction return line L6: Additional gas supply line for evaporation gas

Claims (12)

A pump for supplying the liquefied gas stored in the liquefied gas storage tank to the propulsion engine;
An evaporative gas compressor for compressing the evaporated gas generated in the liquefied gas storage tank;
A heat exchanger for exchanging heat between the liquefied gas supplied from the pump and the evaporation gas supplied from the evaporation gas compressor; And
And an evaporative gas circulation line having the heat exchanger formed to return the evaporated gas generated in the liquefied gas storage tank back to the liquefied gas storage tank,
The evaporation gas,
Wherein at least a portion of the heat exchanger is re-liquefied and returned to the liquefied gas storage tank by the evaporative gas circulation line without heat exchange with a separate refrigerant. The method according to claim 1,
And a control unit controlling the flow of the evaporated gas heat-exchanged in the heat exchanger according to the load of the propulsion engine to re-liquefy the evaporated gas supplied from the evaporative gas compressor without a re-liquefier having another refrigerant. Gas processing system. 3. The apparatus of claim 2,
And controlling the fully re-liquefied evaporated gas in the heat exchanger to be supplied to the liquefied gas storage tank when the load of the propulsion engine is equal to or greater than a preset load,
And controls so that both the liquid phase and the vapor phase of the partially re-liquefied evaporated gas in the heat exchanger are supplied to the liquefied gas storage tank when the load of the propulsion engine is lower than a preset load. The apparatus according to claim 3,
So that the line speed is 17 to 18 knots. The method of claim 3,
Further comprising a gas-liquid separator for receiving the heat-exchanged vaporized gas from the heat exchanger and separating the vaporized gas into a liquid phase and a vapor phase. 6. The method of claim 5,
A re-liquefied return line connecting the lower side of the gas-liquid separator and the liquefied gas storage tank;
A refill return valve provided on the refill return line;
A flash gas supply line connecting the upper side of the gas-liquid separator and the liquefied gas storage tank; And
Further comprising a flash gas supply valve provided on the flash gas supply line,
Wherein the evaporative gas regression line includes the redistribution return line and the flash gas return line,
Wherein,
When the load of the propulsion engine is equal to or greater than a predetermined load, opening of the re-liquefied return valve is opened and the opening of the flash gas supply valve is closed so that evaporated gas completely re-liquefied in the heat exchanger flows into the liquefied gas storage tank To be supplied,
Wherein when the load of the propulsion engine is lower than a preset load, opening of the re-liquefied return valve and opening of the flash gas supply valve are opened, so that both the liquid phase and the vapor phase of the partially re- And to be supplied to the storage tank. The method according to claim 1,
Further comprising a control unit for controlling the flow of the evaporative gas flowing into the heat exchanger according to the load of the propulsion engine and re-liquefying the evaporative gas supplied from the evaporative gas compressor without a re-liquefier having another refrigerant Gas treatment system. 8. The method of claim 7,
An evaporation gas liquefaction line connecting the liquefied gas storage tank and the heat exchanger and having the evaporative gas compressor; And
Further comprising an evaporative gas addition supply line connecting the liquefied gas storage tank to an evaporation gas consuming source and supplying the evaporation gas generated in the liquefied gas storage tank to the evaporation gas consumption source without a compression means,
Wherein the evaporation gas regression line comprises the evaporation gas liquefaction line,
Wherein,
And controlling the evaporation gas generated from the liquefied gas storage tank to be supplied to the evaporative gas compressor through the evaporation gas liquefaction line when the load of the propulsion engine is equal to or greater than a predetermined load,
And controls the evaporation gas compressor so that at least a part of the evaporation gas generated in the liquefied gas storage tank is supplied to the evaporative gas compressor through the evaporation gas liquefaction line when the load of the propulsion engine is less than a preset load, And the remaining of the evaporated gas to be supplied to the evaporation gas consumption source through the evaporation gas addition supply line. 9. The method of claim 8,
An evaporation gas first supply valve provided on the evaporation gas liquefaction line; And
And an evaporation gas second supply valve provided on the evaporation gas addition supply line,
Wherein,
Opening the opening of the evaporation gas first supply valve and closing the opening of the evaporation gas second supply valve when the load of the propulsion engine is equal to or greater than a preset load, To be supplied to the evaporation gas liquefaction line,
Reducing the opening of the evaporation gas first supply valve and opening the opening of the evaporation gas second supply valve when the load of the propulsion engine is less than a predetermined load to prevent at least part of the evaporation gas generated in the liquefied gas storage tank Is supplied to the evaporation gas liquefaction line, and the rest is supplied to the evaporation gas addition supply line. The method as claimed in claim 9,
So that the line speed is 17 to 18 knots. The method according to claim 1,
A liquefied gas supply line connecting the liquefied gas storage tank and the propulsion engine;
An evaporation gas supply line connecting the liquefied gas storage tank and the evaporation gas consumption site; And
And an evaporation gas liquefaction line branched off from the evaporation gas compressor on the evaporation gas supply line and connected to the heat exchanger,
Wherein the evaporation gas regression line includes at least a portion of the evaporation gas supply line,
The evaporation gas liquefaction line may comprise:
And is connected to the liquefied gas storage tank without the gas-liquid separator so that the completely re-liquefied evaporated gas in the heat exchanger is returned to the liquefied gas storage tank. 12. A vessel comprising the gas treatment system of any one of claims 1 to 11.

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