KR102046600B1 - Liquefied Gas Treatment System and Liquefied Gas Carrier having the same - Google Patents

Abstract

The present invention relates to a liquefied gas treatment system and a liquefied gas carrier having the same. The liquefied gas treatment system of the present invention includes: a heat exchanger heat-exchanging first liquefied gas supplied to a demand source from a first liquefied gas storage tank and boil off gas generated in a second liquefied gas storage tank; a separator separating liquid and vapor from the boil off gas cooled via the heat exchanger; and a buffer tank heat-exchanging the first liquefied gas filled therein and the boil off gas separated in the separator in a vapor and liquid manner, wherein the boil off gas is reliquefied via the heat exchanger and the buffer tank to be collected to the second liquefied gas storage tank. The first liquefied gas is heated via the heat exchanger and the buffer tank.

Description

Liquefied Gas Treatment System and Liquefied Gas Carrier having the same

The present invention relates to a liquefied gas treatment system and a liquefied gas carrier having the same.

As the demand for reducing environmental pollutants such as SO _x , NO _x , and CO ₂ generated during operation on ships increases, and these environmental issues and regulations on ships and exhaust emissions are tightened, existing fuel oils Instead, ships that use clean fuel, LNG (Liquefied Natural Gas), are being used as propellant fuel. Ships using such LNG as propulsion fuel should have a separate device for fueling LNG.

In order to reduce the volume of the first liquefied gas storage tank of a vessel using LNG as a propulsion fuel, fuel is stored as LNG, which is a liquefied natural gas, and LNG is vaporized through a fuel supply device to use LNG as a fuel. In this case, all the cold heat generated is discharged to the outside.

Meanwhile, a carrier that stores and transports liquefied gas, which is generally stored in a liquid state, such as LPG (Liquefied Petroleum Gas), ethylene, or ammonia in a liquefied gas storage tank, evaporates liquefied gas due to natural vapor intrusion during operation. Boil off gas (BOG) is generated to increase the internal pressure of the liquefied gas storage tank, and to re-liquefy the boil-off gas to eliminate the risk of tank damage caused by the increased pressure inside the liquefied gas storage tank. Various ways to recycle the boil-off gas, such as re-liquefying it and recovering it into a liquefied gas storage tank, have been studied.

However, the reliquefaction apparatus applied to the existing liquefied gas carriers is to compress the evaporated gas generated in the liquefied gas storage tank and liquefy using sea water. The compressor for compressing the evaporated gas is composed of two or three stages. An inter-cooler is installed between each compressor to lower the temperature of the fluid, and a portion of the liquefied gas liquefied using seawater enters the inter-cooler via Joule Thompson (JT). The flash gas of temperature is mixed with the hot gas passing through the compressor to re-liquefy the boil-off gas by lowering the temperature. However, such a conventional reliquefaction apparatus includes a complex component as described above, alone or It is configured in parallel and has the problem of increasing energy consumption and system construction cost.

The present invention was created to solve the problems of the prior art as described above, an object of the present invention is to recycle the boil-off gas generated from LPG stored in the second liquefied gas storage tank using LNG stored in the first liquefied gas storage tank. By liquefying, it is possible to simplify the components of the reliquefaction apparatus as well as to provide a liquefied gas treatment system and a liquefied gas carrier having the same that can reduce the energy consumption and system construction cost of the reliquefaction apparatus.

Another object of the present invention is to increase the temperature of the LNG supplied to the engine from the first liquefied gas storage tank by using the boiled gas generated from the LPG stored in the second liquefied gas storage tank, when the LNG to be used as the fuel of the engine is vaporized It is to provide a liquefied gas treatment system and a liquefied gas carrier having the same can easily obtain the required amount of heat.

A liquefied gas processing system according to an aspect of the present invention includes a heat exchanger for heat-exchanging the liquefied gas generated in the first liquefied gas and the second liquefied gas storage tank supplied to the demand from the first liquefied gas storage tank; A separator for separating a liquid phase and a gaseous phase from the cooled boil-off gas while passing through the heat exchanger; And a buffer tank configured to heat-exchange the first liquefied gas filled therein and the boil-off gas separated from the gas-liquid separator in the separator, wherein the boil-off gas is re-liquefied while passing through the heat exchanger and the buffer tank. Recovered to the storage tank, the first liquefied gas is characterized in that the heating via the heat exchanger and the buffer tank.

Specifically, the first liquefied gas is LNG, the second liquefied gas is LPG, the heat exchanger is an LNG-BOG (LPG) heat exchanger, the buffer tank is to perform the LNG-BOG (LPG) heat exchanger function. Can be.

Specifically, a fuel supply device is provided in a first line connected from the first liquefied gas storage tank to the demand destination, and the fuel supply device includes: the heat exchanger provided on the first line; The buffer tank provided on the first line; A pump provided on the first line between the first liquefied gas storage tank and the buffer tank to pressurize the first liquefied gas; And a heater provided on the first line between the heat exchanger and the demand source and heating the first liquefied gas to a temperature required by the demand destination.

Specifically, the second line is connected to the upper end of the second liquefied gas storage tank, one end is connected to the inside of the second liquefied gas storage tank, the reliquefaction apparatus is provided, the reliquefaction apparatus, The heat exchanger provided on the second line; The buffer tank provided on the second line; The separator provided on the second line between the heat exchanger and the buffer tank; And a compressor provided on the second line between the second liquefied gas storage tank and the heat exchanger to pressurize the boil-off gas.

Specifically, a third line having one end connected to the separator and the other end connected to the second line between the buffer tank and the second liquefied gas storage tank is provided, and a second liquid phase separated from the separator The liquefied gas may be recovered to the second liquefied gas storage tank through the third line.

In detail, the second line may pass through the buffer tank filled with the first liquefied gas, and the second line may pass through a shell-coil type.

The liquefied gas carrier according to another aspect of the present invention is characterized by including the liquefied gas treatment system described above.

The liquefied gas treatment system and the liquefied gas carrier having the same according to the present invention is configured such that the fuel supply device and the reliquefaction device are connected to each other, by using the first liquefied gas stored in the first liquefied gas storage tank to the second liquefied gas storage tank. It is possible to improve the reliquefaction efficiency of the boil-off gas generated in the above, thereby simplifying the components of the reliquefaction apparatus as well as reducing the energy consumption and system construction cost of the reliquefaction apparatus.

In addition, the liquefied gas processing system according to the present invention and the liquefied gas carrier ship having the same is configured so that the fuel supply device and the reliquefaction device is connected, the first liquefied gas supplied to the engine from the first liquefied gas storage tank is the second liquefaction Heat-exchanged with the boil-off gas generated in the gas storage tank, the first liquefied gas to be used as the fuel of the engine can be easily obtained from the boil-off gas evaporation gas, it is possible to improve the LNG fuel energy efficiency supplied to the engine .

1 is a view showing a liquefied gas carrier ship applying the liquefied gas treatment system according to the present invention.
2 is a conceptual diagram of a liquefied gas treatment system according to a first embodiment of the present invention.
3 is a conceptual diagram of a liquefied gas treatment system according to a second embodiment of the present invention.
4 is a conceptual diagram of a liquefied gas treatment system according to a third embodiment of the present invention.
5 is a conceptual diagram of a liquefied gas treatment system according to a fourth embodiment of the present invention.
6 is a conceptual diagram of a liquefied gas treatment system according to a fifth embodiment of the present invention.
7 is a conceptual diagram of a liquefied gas treatment system according to a sixth embodiment of the present invention.
8 is a conceptual diagram of a liquefied gas treatment system according to a seventh embodiment of the present invention.
9 is a conceptual diagram of a liquefied gas treatment system according to an eighth embodiment of the present invention.
10 is a conceptual diagram of a liquefied gas treatment system according to a ninth embodiment of the present invention.

The objects, specific advantages and novel features of the present invention will become more apparent from the following detailed description and preferred embodiments in conjunction with the accompanying drawings. In the present specification, in adding reference numerals to the components of each drawing, it should be noted that the same components as possible, even if displayed on different drawings have the same number as possible. In addition, in describing the present invention, if it is determined that the detailed description of the related known technology may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

Hereinafter, in the present specification, liquefied gas may be used to encompass all gaseous fuels that are generally stored in a liquid state, such as LNG, LPG, ethylene, ammonia, and the like. Can be expressed as This can be applied to boil-off gas (BOG) as well.

In the present invention, LNG is the first liquefied gas and LPG may be referred to as the second liquefied gas, wherein the boiling point of the first liquefied gas may be relatively lower than the second liquefied gas. Here, the first liquefied gas may be limited to methane, which is a main component of LNG, and the second liquefied gas may be limited to propane, butane and ethane, which are components of LPG.

Of course, the present invention is not limited to the first liquefied gas and the second liquefied gas to LNG and LPG, respectively, the first liquefied gas and the second liquefied gas will mean not only LNG and LPG but also all liquefied gases having different boiling points. Can be.

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

1 is a view showing a liquefied gas carrier ship applying the liquefied gas treatment system according to the present invention.

As shown in FIG. 1, the liquefied gas carrier ship 1 uses the first liquefied gas stored in a liquid state in the first liquefied gas storage tank 20 as a fuel of the engine 30, and inside the hull 10. The second liquid liquefied gas in a liquid state in the plurality of second liquefied gas storage tank 40 provided may be a vessel for transporting from the production site to various consumption sites.

The liquefied gas carrier 1 is a fuel supply device and a second liquefied gas storage for vaporizing the first liquefied gas to use the first liquefied gas stored in the first liquefied gas storage tank 20 as the fuel of the engine 30 Various liquefied gas treatment systems 100, 200, 300, 400, 500, 600, 700, 800, and 900 may be provided to be connected to a reliquefaction apparatus for liquefying boil-off gas generated in the tank 40. Here, the configuration of each of the fuel supply device and the reliquefaction device and their associated configuration can be seen by referring to FIGS. 2 to 10.

In the above, the first liquefied gas storage tank 20 stores the first liquefied gas in a liquid state to be supplied as fuel to the engine 30. The first liquefied gas storage tank 20 should store the first liquefied gas in a liquid state, in which case the first liquefied gas storage tank 20 may have a pressure tank form. The first liquefied gas storage tank 20 may be installed on a ship, such as a liquefied gas carrier (1) using the first liquefied gas as the fuel of the engine, or may be installed on land. When the first liquefied gas stored in the first liquefied gas storage tank 20 is LNG, the LNG stored in the LNG storage tank 20 has a boiling point of −162 ° C. under 1 atmosphere.

The engine 30 receives the first liquefied gas from the first liquefied gas storage tank 20 to generate power to drive the propeller of the liquefied gas carrier 1, and may be an XDF, DFDE, or MEGI engine.

The engine 30 may be an engine for driving a propeller, but may be an engine for power generation or an engine for generating other power. In other words, the present embodiment does not particularly limit the type of the engine 30. However, the engine 30 may be an internal combustion engine generating a driving force by combustion of the first liquefied gas.

Of course, the present invention describes a case where the demand destination using the first liquefied gas as the fuel is the engine 30, but the present invention is not limited thereto. Of course, the gas burning unit may include a gas compression unit (GCU), a boiler, and the like.

At least one second liquefied gas storage tank 40 may be installed on a ship or onshore, and may store the second liquefied gas in a liquid state. In the present invention, a case where the second liquefied gas storage tank 40 is provided inside the hull 10 will be described.

When the second liquefied gas stored in the second liquefied gas storage tank 40 is LPG, among the components of LPG stored in the LPG storage tank 40, when boiling points are arranged in descending order, ethane (C ₂ H ₆ ) The boiling point is -89.0 deg. C at 1 atmosphere, propane (C ₃ H ₈ ) is -42 deg. C at 1 atmosphere, and butane (C ₄ H ₁₀ ) is -0.5 deg. C at 1 atmosphere. As such, even though LPG is stored for each component or stored in a mixed state, the boiling point is very high, considering that the boiling point of LNG stored in the LNG storage tank 20 is -162 ° C under 1 atmosphere.

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

As shown in FIG. 2, the liquefied gas treatment system 100 according to the first embodiment of the present invention may be provided in a liquefied gas carrier 1, and includes a first pump 110, a heat exchanger 120, A heater 130, a blower 140, a separator 150, a second pump 160, a reliquefaction unit 170, and a temperature control valve 180 are included.

In the above, the first pump 110, the heat exchanger 120, the heater 130 may be components of the fuel supply device, the heat exchanger 120, blower 140, separator 150, the second pump 160, the reliquefaction unit 170 may be components of the reliquefaction apparatus, and the heat exchanger 120 used in common may be configured to link the fuel supply apparatus and the reliquefaction apparatus.

The above components may be provided on the first line 101, the second line 102, and the third line 103.

Specifically, the first line 101 may be connected to the engine 30 from the first liquefied gas storage tank 20, the first liquefied gas stored in the first liquefied gas storage tank 20 to the engine 30. It can be configured to be able to supply. Each of the first pump 110, the heat exchanger 120, and the heater 130 may be provided on the first line 101.

The second line 102 may have one end connected to an upper portion of the second liquefied gas storage tank 40, the other end connected to an inside of the second liquefied gas storage tank 40, and a second liquefied gas storage tank ( 40 may be configured to re-liquefy the boil-off gas generated in the interior. The heat exchanger 120, the blower 140, the separator 150, and the second pump 160 may be provided on the second line 102.

The third line 103 has one end connected to the second line 102 between the second liquefied gas storage tank 40 and the blower 140 to be described later, and the other end of the third line 160 and the second pump 160 to be described later. It may be connected to the second line 102 between the two liquefied gas storage tank 40, it may be configured to re-liquefy the boil-off gas generated in the second liquefied gas storage tank 40. The reliquefaction unit 170 may be provided on the third line 103.

The first pump 110 is provided on the first line 101 between the first liquefied gas storage tank 20 and the heat exchanger 120 to be described later, the first liquefied gas stored in the first liquefied gas storage tank 20 The first liquefied gas discharged from the first liquefied gas storage tank 20 may be pressurized to a pressure required by the engine 30 so as to supply the to the engine 30. Of course, the pressure required by the engine 30 may vary depending on the type of the engine 30, for example, XDF, DFDE, MEGI engine, or the like.

The heat exchanger 120 may be provided on the first line 101 and the second line 102, and may be an LNG-BOG (LPG) heat exchanger when the first liquefied gas is LNG and the second liquefied gas is LPG. have.

Specifically, the heat exchanger 120 may be positioned between the first pump 110 and the heater 130 to be described later in the first line 101, and the blower 140 to be described later in the second line 102. It may be located between the separators 150 to be described later.

In the heat exchanger 120, the first liquefied gas having a relatively low boiling point and the second liquefied gas storage tank 40 supplied from the first liquefied gas storage tank 20 to the engine 30 through the first line 101. ) Is generated from the second liquefied gas stored in the relatively high boiling point and the boil-off gas supplied through the second line 102 for reliquefaction is mutually heat exchanged, so that the engine (via the heater 130 to be described later) The first liquefied gas supplied to 30 may obtain heat by the heat of the boil-off gas generated from the second liquefied gas to reduce thermal energy when the heater 130 is heated to a temperature required by the engine 30. In addition, the boil-off gas generated in the second liquefied gas storage tank 40 is re-liquefied by obtaining cold heat of the first liquefied gas, thereby increasing the re-liquefaction efficiency of the boil-off gas generated inside the second liquefied gas storage tank 40. You can.

The heater 130 may be provided on the first line 101 between the engine 30 and the heat exchanger 120, and receives the first liquefied gas supplied from the first liquefied gas storage tank 20 to the engine 30. Can be heated to the temperature required. In the present embodiment, since the first liquefied gas supplied to the heater 130 is heated while passing through the heat exchanger 120 provided upstream of the heater 130, heat energy is generated when the engine 30 is heated to a required temperature. You can save.

The heater 130 is a waste heat generated from steam supplied through a boiler (not shown), glycol water supplied from a glycol heater (not shown), electrical energy, or a generator or other equipment provided in a ship. The first liquefied gas can be heated.

The blower 140 may be provided on the second line 102 between the second liquefied gas storage tank 40 and the heat exchanger 120, and is generated and discharged inside the second liquefied gas storage tank 40. Pressurized evaporated gas to be supplied to the heat exchanger (120). This blower 140 can reduce power consumption by up to 58% compared to compressors typically used in reliquefaction equipment.

Separator 150 may be provided on the second line 102 between the heat exchanger 120 and the second pump 160 to be described later, and the liquid and gaseous phase in the cooled evaporated gas via the heat exchanger 120 Can be separated. The separator 150 may recover the second liquefied gas of the liquid phase separated from the gas-liquid to the second liquefied gas storage tank 40.

The second pump 160 may be provided on the second line 102 between the separator 150 and the second liquefied gas storage tank 40, and the second liquefied gas separated into the liquid phase from the separator 150 may be provided. The second liquefied gas storage tank 40 may be pressurized to be easily recovered. The second pump 160 may be provided at the rear end of the separator 150 to turn on / off the operation according to the level of the second liquefied gas inside the separator 150.

The second liquefied gas separated into the liquid phase in the separator 150 may be recovered to the second liquefied gas storage tank 40 by the compression ratio of the blower 140 and the pressurization ratio of the second pump 160. The second pump 160 may compensate for a problem that may occur due to the low compression ratio.

The reliquefaction unit 170 may be provided on the third line 103 and reliquefy the boil-off gas generated in the second liquefied gas storage tank 40.

The reliquefaction unit 170 may be operated to be compatible with the heat exchanger 120, for example, may be operated when it is impossible to completely reliquefy the boil-off gas in the heat exchanger 120.

The temperature control valve 180 may be provided on the second line 102 between the heat exchanger 120 and the separator 150.

The temperature control valve 180 is provided at the front end of the separator 150 to completely reliquefy the evaporated gas generated in the second liquefied gas storage tank 40 in the heat exchanger 120, the internal pressure of the separator 150 The degree of opening can be controlled according to the temperature of the front end of the temperature control valve 180. According to the trajectory of the temperature control valve 180, the amount of the boil-off gas introduced into the heat exchanger 120 is adjusted to completely re-liquefy the boil-off gas.

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

As shown in FIG. 3, the liquefied gas treatment system 200 according to the second embodiment of the present invention may be provided in the liquefied gas carrier ship 1, and includes a first pump 210 and a heat exchanger 220. , Heater 230, second pump 240, separator 250, reliquefaction unit 260, and injection nozzle 270.

In the above, the first pump 210, the heat exchanger 220, the heater 230 may be components of the fuel supply device, the heat exchanger 220, the second pump 240, the separator 250, ash The liquefaction unit 260 and the injection nozzle 270 may be components of the reliquefaction apparatus, and the heat exchanger 220 used in common may be configured to link the fuel supply apparatus and the reliquefaction apparatus.

The above components may be provided on the first line 201, the second line 202, and the third line 203.

Specifically, the first line 201 may be connected to the engine 30 from the first liquefied gas storage tank 20, and heats the first liquefied gas stored in the first liquefied gas storage tank 20 to engine 30. It can be configured to be able to supply). Each of the first pump 210, the heat exchanger 220, and the heater 230 may be provided on the first line 201.

The second line 202 is connected to a second pump 240 to be described later, one end of which is provided in the inner bottom portion of the second liquefied gas storage tank 40, and the other end of the second liquefied gas storage tank 40 It may be connected to the injection nozzle 270 to be described later provided in the inner ceiling portion, it may be configured to circulate the second liquefied gas stored in the second liquefied gas storage tank 40. A second pump 240, a heat exchanger 220, a separator 250, and a spray nozzle 270 may be provided on the second line 102.

One end of the third line 203 is connected to an upper portion of the second liquefied gas storage tank 40, and the other end is provided at a spray nozzle 270 which will be described later on an inner ceiling portion of the second liquefied gas storage tank 40. It may be connected to, and may be configured to re-liquefy the boil-off gas generated inside the second liquefied gas storage tank 40. The reliquefaction unit 260 may be provided on the third line 203.

The first pump 210 may be provided on the first line 201 between the first liquefied gas storage tank 20 and the heat exchanger 220 to be described later, the same as the pump 110 of the first embodiment or As similar components, the description will be omitted here to avoid duplication of description.

The heat exchanger 220 may be provided on the first line 201 and the second line 202, and may be an LNG-LPG heat exchanger when the first liquefied gas is LNG and the second liquefied gas is LPG.

Specifically, the heat exchanger 220 may be positioned between the first pump 210 and the heater 230 to be described later in the first line 201, and the second pump 240 to be described later in the second line 202. ) And the separator 250 to be described later.

In the heat exchanger 220, the first liquefied gas having a relatively low boiling point and the second liquefied gas storage tank 40 supplied from the first liquefied gas storage tank 20 to the engine 30 through the first line 201. The second liquefied gas, which has a relatively high boiling point, which is recovered from the second liquefied gas storage tank 40 through the second line 202, is mutually heat-exchanged, so that the engine 30 is passed through the heater 230 to be described later. The first liquefied gas to be supplied to the heat is saved by the heat of the second liquefied gas to heat the heater 230 to the temperature required by the engine 30 to reduce the thermal energy, the second liquefied gas Since the second liquefied gas recovered to the storage tank 40 is cooled to obtain the cold heat of the first liquefied gas to be in a supercooled state, generation of the boil-off gas in the second liquefied gas storage tank 40 can be essentially suppressed.

The heater 230 may be provided on the first line 201 between the engine 30 and the heat exchanger 220, and the same or similar components as the heater 130 of the first embodiment are not described herein. The description will be omitted to avoid.

The second pump 240 may be provided at an inner bottom portion of the second liquefied gas storage tank 40 to be connected to the second line 202, and heat exchange the second liquefied gas stored in the second liquefied gas storage tank 40. The second liquefied gas may be pressurized to be recovered to the second liquefied gas storage tank 40 via the gas 220, the separator 250 to be described later, and the injection nozzle 270 to be described later.

Separator 250 may be provided on the second line 202 between the heat exchanger 220 and the injection nozzle 270 to be described later, the liquid and gas phase in the second liquefied gas via the heat exchanger 220 Can be separated to extract the second liquefied gas. Since the second liquefied gas via the heat exchanger 220 is supercooled by the first liquefied gas, the second liquefied gas may not be present inside the separator 250. The separator 250 may recover the second liquefied gas of the liquid phase separated from the gas-liquid to the second liquefied gas storage tank 40.

The reliquefaction unit 260 may be provided on the third line 203 and reliquefy the boil-off gas generated in the second liquefied gas storage tank 40.

The injection nozzle 270 may be provided in plural in the ceiling portion of the second liquefied gas storage tank 40, and may be connected to the second line 202 and the third line 203. Injection nozzle 270 is a second liquefied gas in the subcooled state supplied through the second line 202 and / or the second liquefied gas separated in the liquid phase in the separator 150 supplied through the third line (203) The upper part of the second liquefied gas storage tank 40 may be injected, and thus, the generation of the boil-off gas in the second liquefied gas storage tank 40 may be suppressed.

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

As shown in FIG. 4, the liquefied gas treatment system 300 according to the third exemplary embodiment of the present invention may be provided in the liquefied gas carrier 1, and includes a pump 310, a heat exchanger 320, and a compressor ( 330, separator 340, and reliquefaction unit 350.

In the above, the pump 310, the heat exchanger 320 may be components of the fuel supply device, the heat exchanger 320, the compressor 330, the separator 340, the reliquefaction unit 350 is a reliquefaction device The heat exchanger 320 used in common may be configured to link the fuel supply device and the reliquefaction device.

The above components may be provided on the first line 301, the second line 302, and the third line 303.

Specifically, the first line 301 may be connected from the first liquefied gas storage tank 20 to the engine 30, and heats the first liquefied gas stored in the first liquefied gas storage tank 20 to engine 30. It can be configured to be able to supply). Each of the pump 310 and the heat exchanger 320 may be provided on the first line 101.

One end of the second line 302 may be connected to the upper portion of the second liquefied gas storage tank 40, and the other end thereof may be connected to the inside of the second liquefied gas storage tank 40, and the second liquefied gas storage tank ( 40 may be configured to re-liquefy the boil-off gas generated in the interior. The compressor 330, the heat exchanger 320, and the separator 340 may be provided on the second line 302.

The third line 303 is connected to the second line 302 between the compressor 330 to be described later and the heat exchanger 320 to be described later, and the separator 340 and the second liquefied gas storage to be described later. It may be connected to the second line 302 between the tank 40, it may be configured to re-liquefy the boil-off gas generated in the second liquefied gas storage tank 40. The reliquefaction unit 350 may be provided on the third line 303.

The pump 310 may be provided on the first line 301 between the first liquefied gas storage tank 20 and the heat exchanger 320 to be described later, and the pumps 110 and 210 of the first to second embodiments. The same or similar elements as in the following description will be omitted here in order to avoid duplication of description.

The heat exchanger 320 may be provided on the first line 301 and the second line 302, and may be an LNG-BOG (LPG) heat exchanger when the first liquefied gas is LNG and the second liquefied gas is LPG. have.

Specifically, the heat exchanger 320 may be located between the pump 310 and the engine 30 in the first line 301, and the compressor 330 to be described later and the separator (to be described later) in the second line 302. 340 may be located between.

In the heat exchanger 320, the first liquefied gas having a relatively low boiling point and the second liquefied gas storage tank 40 supplied from the first liquefied gas storage tank 20 to the engine 30 through the first line 301. The first liquefaction gas is generated from the second liquefied gas stored in the inside of the) and the boil-off gas supplied through the second line 302 for reliquefaction is mutually heat exchanged, so that the first liquefaction gas is supplied to the engine 30. The gas is heated to a temperature required by the engine 30 by the heat of the boil-off gas generated from the second liquefied gas to reduce the thermal energy, and the boil-off gas generated in the second liquefied gas storage tank 40 By re-liquefying by obtaining cold heat of the first liquefied gas, it is possible to increase the reliquefaction efficiency of the boil-off gas generated in the second liquefied gas storage tank 40.

In the present embodiment, it is described that the heating means such as the heaters 130 and 230 of the first or second embodiment is omitted between the heat exchanger 320 and the engine 30, but the present invention is not limited thereto. Alternatively, a heater similar or identical to the heaters 130 and 230 of the second embodiment may be provided.

The compressor 330 may be provided on the second line 302 between the second liquefied gas storage tank 40 and the heat exchanger 320, and is generated and discharged inside the second liquefied gas storage tank 40. By pressurizing the evaporated gas to be supplied to the heat exchanger 320 and the reliquefaction unit 350 to be described later. The compressor 330 may be provided in plural and may be arranged in parallel on the second line 302.

Separator 340 may be provided on the second line 302 between the heat exchanger 320 and the second liquefied gas storage tank 40, the liquid and the liquid in the evaporated gas cooled via the heat exchanger 120 The gas phase can be separated. The separator 340 may recover the second liquefied gas of the liquid phase separated from the gas-liquid to the second liquefied gas storage tank 40.

The reliquefaction unit 350 may be provided on the third line 303 and reliquefy the boil-off gas generated in the second liquefied gas storage tank 40 supplied from the compressor 330.

The reliquefaction unit 350 may be operated to be compatible with the heat exchanger 320, for example, may be operated when it is not possible to completely re-liquefy the boil-off gas in the heat exchanger (320).

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

As shown in FIG. 5, the liquefied gas treatment system 400 according to the fourth embodiment of the present invention may be provided in the liquefied gas carrier 1, and includes a pump 410, a heat exchanger 420, and a buffer tank. 430, heater 440, compressor 450, separator 460.

In the above, the pump 410, the heat exchanger 420, the buffer tank 430, the heater 440 may be components of the fuel supply device, the heat exchanger 420, the buffer tank 430, the compressor 450 The separator 460 may be components of the reliquefaction apparatus, and the heat exchanger 420 and the buffer tank 430 which are commonly used may be configured to link the fuel supply apparatus and the reliquefaction apparatus.

The above components may be provided on the first line 401, the second line 402, and the third line 403.

Specifically, the first line 401 may be connected to the engine 30 from the first liquefied gas storage tank 20, and heats the first liquefied gas stored in the first liquefied gas storage tank 20 to engine 30. It can be configured to be able to supply). The pump 410, the buffer tank 430, the heat exchanger 420, and the heater 440 may be provided on the first line 4101.

One end of the second line 402 may be connected to an upper portion of the second liquefied gas storage tank 40, and the other end may be connected to an inside of the second liquefied gas storage tank 40. 40 may be configured to re-liquefy the boil-off gas generated in the interior. The compressor 450, the heat exchanger 420, the separator 460, and the buffer tank 430 may be provided on the second line 402.

One end of the third line 403 may be connected to the separator 460 to be described later, and the other end thereof may be connected to the second line 402 between the buffer tank 430 and the second liquefied gas storage tank 40 to be described later. It may be configured to recover the second liquefied gas separated into the liquid phase in the separator 460 to be described later to the second liquefied gas storage tank 40.

The pump 410 may be provided on the first line 401 between the first liquefied gas storage tank 20 and the buffer tank 430 to be described later, and the pumps 110, 210, The same or similar components as those of 310 may be omitted here to avoid duplication of description.

The second heat exchanger 420 may be provided on the first line 401 and the second line 402, and the LNG-BOG (LPG) heat exchanger when the first liquefied gas is LNG and the second liquefied gas is LPG It may be a flag.

Specifically, the heat exchanger 420 may be located between the buffer tank 430 to be described later and the heater 440 to be described later in the first line 401, and the compressor 450 to be described later in the second line 402. And a separator 460 to be described later.

In the heat exchanger 420, the first liquefied gas having a relatively low boiling point and the second liquefied gas storage tank 40 which are supplied from the first liquefied gas storage tank 20 to the engine 30 through the first line 401. ) Is generated from the second liquefied gas stored in the relatively high boiling point and circulated through the second line 402 for reliquefaction. The first liquefied gas supplied to 30 may obtain heat by the heat of the boiled gas generated from the second liquefied gas to reduce the thermal energy when the heater 440 is heated to the temperature required by the engine 30. In addition, the boil-off gas generated in the second liquefied gas storage tank 40 is re-liquefied by obtaining cold heat of the first liquefied gas, thereby increasing the re-liquefaction efficiency of the boil-off gas generated inside the second liquefied gas storage tank 40. You can.

The buffer tank 430 may be provided on the first line 401 and the second line 402. The first liquefied gas is filled in a predetermined amount through the first line 401, and the first liquefied gas is The second line 402 may be configured to pass through the filled interior. The second line 402 penetrating the inside of the buffer tank 430 may have various forms including a shell-coil type. The buffer tank 430 may perform an LNG-BOG (LPG) heat exchanger function when the first liquefied gas is LNG and the second liquefied gas is LPG.

In detail, the buffer tank 430 may be located between the pump 410 and the heat exchanger 420 to be described later in the first line 401, and the separator 460 and the second to be described later in the second line 402. It can be located between the two liquefied gas storage tank (40).

In the buffer tank 430, the first liquefied gas having a relatively low boiling point supplied from the first liquefied gas storage tank 20 to the engine 30 through the first line 401, and the gas liquid in the separator 460 to be described later. As the boil-off gas of the second liquefied gas having a relatively high boiling point separated and circulated through the second line 402 is exchanged with each other, the first liquefied gas supplied to the engine 30 is heated by the heat of the boil-off gas. The engine 30 is heated to a temperature required to reduce the thermal energy, and the boil-off gas generated in the second liquefied gas storage tank 40 obtains the cold heat of the first liquefied gas and reliquefies the second liquefied gas. It is possible to increase the reliquefaction efficiency of the boil-off gas generated in the gas storage tank 40.

Similar to the heat exchanger 420, the buffer tank 430 heats the first liquefied gas supplied from the first liquefied gas storage tank 20 to the engine 30 to a temperature required by the engine 30, and The function of cooling the boil-off gas generated in the two-liquefied gas storage tank 40 to a temperature capable of re-liquefying can be performed, whereby this embodiment is the first by the heat exchanger 420 and the buffer tank 430 The heating of the liquefied gas is carried out in two times, and the reliquefaction of the boiled gas is made in two times, so that it is heated to a temperature required by the engine 30 to further reduce thermal energy, and store the second liquefied gas. The reliquefaction efficiency of the boil-off gas generated in the tank 40 can be further increased.

The amount of reliquefaction of the boil-off gas generated in the second liquefied gas storage tank 40 may be changed according to the load of the engine 20, because the amount of the first liquefied gas utilized as cold heat is changed. That is, when the load of the engine 20 is large or small, there is a problem that the amount of reliquefaction must be large or small, which is caused by adjusting the level of the first liquefied gas filled in the buffer tank 430. You can control the level. In other words, when the level of the first liquefied gas filled in the buffer tank 430 is increased or decreased, the area where the second line 402 penetrating the interior of the buffer tank 430 is in contact with the first liquefied gas is increased or decreased. The amount of reliquefaction can be controlled.

At the rear end of the buffer tank 430, a pump for pressurization purpose may be additionally installed according to the required pressure of the engine 20.

The first liquefied gas filled in the buffer tank 430 may be vaporized by heat exchange with the boil-off gas supplied from the second liquefied gas storage tank 40, the first liquefied vaporized in the buffer tank 430 The boil-off gas of the gas may be recovered to the first liquefied gas storage tank 20 through the fourth line 404 or supplied to the heater 440 through the fifth line 405.

The heater 440 may be provided on the first line 401 between the engine 30 and the heat exchanger 420, and may be the same or similar components as the heaters 130 and 230 of the first to second embodiments. Here, the description will be omitted to avoid duplication.

The compressor 450 may be provided on the second line 402 between the second liquefied gas storage tank 40 and the heat exchanger 420, and is generated and discharged inside the second liquefied gas storage tank 40. Pressurized evaporated gas to be supplied to the heat exchanger (420).

The separator 460 may be provided on the second line 402 between the heat exchanger 420 and the buffer tank 430, and may separate the liquid phase and the gaseous phase from the cooled boiled gas via the heat exchanger 420. Can be. The separator 460 may supply the vaporized gaseous gas separated from the gas-liquid gas to the buffer tank 430, and recover the second liquefied gas of the gas-liquid separated liquid to the second liquefied gas storage tank 40. .

That is, the boil-off gas separated by the gaseous phase in the separator 460 may be supplied to the butter tank 430 through the second line 402 to be re-liquefied and then recovered to the second liquefied gas storage tank 40. In addition, the second liquefied gas separated into the liquid phase in the separator 460 may be recovered to the second liquefied gas storage tank 40 through the third line 403.

6 is a conceptual diagram of a liquefied gas treatment system according to a fifth embodiment of the present invention.

As shown in FIG. 6, the liquefied gas treatment system 500 according to the fifth embodiment of the present invention may be provided in the liquefied gas carrier ship 1, and includes a first pump 510, a heat exchanger 520, The heater 530, a knock out drum 540, a second pump 550, and a level control valve 560 are included.

In the above description, the first pump 510, the heat exchanger 520, and the heater 530 may be components of a fuel supply device, the heat exchanger 520, the knockout drum 540, the second pump 550, The level control valve 560 may be components of the reliquefaction apparatus, and the heat exchanger 520 used in common may be configured to link the fuel supply apparatus and the reliquefaction apparatus.

The above components may be provided on the first line 501, the second line 502, and the third line 503.

Specifically, the first line 501 may be connected from the first liquefied gas storage tank 20 to the engine 30, and heats the first liquefied gas stored in the first liquefied gas storage tank 20 to engine 30. It can be configured to be able to supply). The first pump 510, the heat exchanger 520, and the heater 530 may be provided on the first line 501.

One end of the second line 502 may be connected to the upper portion of the second liquefied gas storage tank 40, and the other end thereof may be connected to the inside of the second liquefied gas storage tank 40, and the second liquefied gas storage tank ( 40 may be configured to re-liquefy the boil-off gas generated in the interior. The knockout drum 540, the second pump 550, and the level control valve 560 may be provided on the second line 502.

The third line 503 has one end connected to the second line 502 between the second liquefied gas storage tank 40 and the second pump 550 to be described later, and the other end to the knockout drum 540 described later. It may be connected, and may be configured to re-liquefy the boil-off gas generated in the second liquefied gas storage tank 40. The heat exchanger 520 may be provided on the third line 503.

The first pump 510 may be provided on the first line 501 between the first liquefied gas storage tank 20 and the heat exchanger 520 to be described later, and the pump 110 of the first to fourth embodiments may be provided. The same or similar components as those of 210, 310, and 410 will be omitted here in order to avoid duplication of description.

The heat exchanger 520 may be provided on the first line 501 and the third line 503, and may be an LNG-LPG heat exchanger when the first liquefied gas is LNG and the second liquefied gas is LPG.

Specifically, the heat exchanger 520 may be located between the first pump 510 and the heater 530 which will be described later in the first line 501, and may be located at a portion of the third line 503.

In the heat exchanger 520, the relatively low boiling point liquefied gas supplied from the first liquefied gas storage tank 20 to the engine 30 through the first line 501 and the knockout drum 540 to be described later will be described. As the second liquefied gas filled with the relatively high boiling point is mutually heat exchanged, the first liquefied gas supplied to the engine 30 via the heater 530 to be described later is the heat of the boil-off gas generated from the second liquefied gas When the heat is obtained by the heat from the heater 530 to the temperature required by the engine 30 to reduce the heat energy, and the evaporated gas generated in the second liquefied gas storage tank 40 is a knockout drum to be described later By reliquefaction at 540, the reliquefaction efficiency of the boil-off gas generated inside the second liquefied gas storage tank 40 can be increased.

The boil-off gas generated in the second liquefied gas storage tank 40 may be re-liquefied in the knockout drum 540 which will be described later, which is the second liquefied gas filled in the knockout drum 540 which will be described later. Re-liquefaction can be achieved by cooling the boil-off gas supplied into the knock-out drum 540 through the second line 502 after the second liquefied gas is in a sub-cooling state. It is.

The heater 530 may be provided on the first line 501 between the engine 30 and the heat exchanger 520, and is the same as the heaters 130, 230, and 440 of the first to second and fourth embodiments. Or similar components, and descriptions thereof will be omitted herein to avoid duplication of description.

The knockout drum 540 may be provided on the second line 502 to supply boil-off gas generated inside the second liquefied gas storage tank 40, and may be connected to the other end of the third line 503 to exchange heat. The second liquefied gas which has become a supercooled state by 520 may be configured to be injected therein. In the present embodiment, instead of directly recovering the subcooled second liquefied gas to the second liquefied gas storage tank 40, the thermal shock of the second liquefied gas storage tank 40 is injected by spraying from the knockout drum 540. To prevent it.

The second liquefied gas filled in the knockout drum 540 becomes a supercooled state through the heat exchanger 520, and the second liquefied gas in the supercooled state is supplied into the knockout drum 540 through the second line 502. It is possible to cool the evaporated gas to be re-liquefied.

The second liquefied gas inside the knockout drum 540 may be filled at the time of loading or using a cargo pump, a conventional reliquefaction apparatus, and the like, and the present embodiment is not limited thereto and may be filled in the knockout drum 540 by various means. Of course, the second liquefied gas can always be filled with a certain amount.

As the second liquefied gas in the supercooled state injected into the knockout drum 540 reliquefies the boil-off gas, the pressure inside the knockout drum 540 is reduced to reduce the evaporated gas generated in the second liquefied gas storage tank 40. May be continuously drawn into free flow along the second line 502. Therefore, in the present embodiment, the knockout drum 540 may serve as a function of the evaporation gas supply equipment of the reliquefaction apparatus, thereby eliminating the evaporation gas supply equipment to be installed in the reliquefaction apparatus including a blower and a compressor.

The second pump 550 may be provided on the second line 502 between the knockout drum 540 and the second liquefied gas storage tank 40, and may receive the second liquefied gas discharged from the knockout drum 540. It may be pressurized to recover to the second liquefied gas storage tank 40 through the second line 502 or to be supplied to the heat exchanger 520 through the third line 503.

The second pump 550 may adjust the flow rate or pressure of the second liquefied gas supplied to the heat exchanger 520.

The level control valve 560 is continuously increased due to the re-liquefaction of the boil-off gas supplied from the second liquefied gas storage tank 40 to the second liquefied gas in the knockout drum 540, the knockout drum 540 inside It may be further provided at the rear end of the second pump 550 to maintain the second level of the liquefied gas level.

The level control valve 560 is a second line 502 between the second pump 540 and the second liquefied gas storage tank 40, specifically, the second pump 540 and the second liquefied gas storage tank 40. ) May be provided on the second line 502 downstream of the connection point of the third line 503.

The level control valve 560 is opened when the level of the second liquefied gas in the knockout drum 540 becomes higher than a predetermined level so that the second liquefied gas is stored in the second liquefied gas storage tank 40 through the second line 502. When it is lower than a predetermined water level and closed, the second liquefied gas may be controlled to be supplied to the heat exchanger 520 through the third line 503.

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

As shown in FIG. 7, the liquefied gas treatment system 600 according to the sixth embodiment of the present invention may be provided in the liquefied gas carrier 1, and includes a first pump 610, a heat exchanger 620, The heater 630, the knockout drum 640, the second pump 650, the level control valve 660, and the compressor 670 are included.

In the above, the first pump 610, the heat exchanger 620, the heater 630, the compressor 670 may be components of the fuel supply device, the heat exchanger 620, knockout drum 640, the second The pump 650 and the level control valve 660 may be components of the reliquefaction apparatus, and the heat exchanger 620 which is used in common may be configured to connect the fuel supply apparatus and the reliquefaction apparatus.

The above components may be provided on the first line 601, the second line 602, the third line 603, and the fourth line 604.

Specifically, the first line 601 may be connected to the engine 30 from the first liquefied gas storage tank 20, and heats the first liquefied gas stored in the first liquefied gas storage tank 20 to engine 30. It can be configured to be able to supply). The first pump 610, the heat exchanger 620, and the heater 630 may be provided on the first line 601.

One end of the second line 602 may be connected to the upper portion of the second liquefied gas storage tank 40, and the other end thereof may be connected to the inside of the second liquefied gas storage tank 40. 40 may be configured to re-liquefy the boil-off gas generated in the interior. The knockout drum 640, the second pump 650, and the level control valve 660 may be provided on the second line 602.

The third line 603 has one end connected to the second line 602 between the second liquefied gas storage tank 40 and the second pump 650 to be described later, and the other end to the knockout drum 640 which will be described later. It may be connected, and may be configured to re-liquefy the boil-off gas generated in the second liquefied gas storage tank 40. The heat exchanger 620 may be provided on the third line 603.

The fourth line 604 may have one end connected to the upper portion of the first liquefied gas storage tank 20, the other end connected to the inside of the first liquefied gas storage tank 20, and the first liquefied gas storage tank ( 20) may be configured to re-liquefy the boil-off gas generated inside. The compressor 670 and the heat exchanger 620 may be provided on the fourth line 604.

The first pump 610 may be provided on the first line 601 between the first liquefied gas storage tank 20 and the heat exchanger 620 to be described later, the same as the pump 510 of the fifth embodiment or As similar components, the description will be omitted here to avoid duplication of description.

The heat exchanger 620 may be provided on the first line 601, the third line 603, and the fourth line 604. When the first liquefied gas is LNG and the second liquefied gas is LPG, LNG- It may be an LPG-BOG (LNG) heat exchanger. That is, the heat exchanger 620 is composed of a three-stream (3-stream), which is a large amount of boil-off gas generated in the first liquefied gas storage tank 20 and the second liquefied gas storage tank 40 It may be suitable when the amount of boil-off gas generated is small.

Specifically, the heat exchanger 620 may be located between the first pump 610 and the heater 630 to be described later in the first line 601, the first liquefied gas storage tank (4) in the fourth line 604 20 may be located between the compressor 670 and a portion of the third line 603.

In the heat exchanger 620, the relatively low boiling point liquefied gas supplied from the first liquefied gas storage tank 20 to the engine 30 through the first line 601, and the knockout drum 640 to be described later. The fourth line 602 is generated from the relatively high boiling point liquefied gas and the relatively high boiling point liquefied gas stored in the first liquefied gas storage tank 20 to reliquefy. As the evaporated gas circulated through the mutual heat exchange is performed, the first liquefied gas supplied to the engine 30 via the heater 630 to be described later is the evaporated gas generated from the first liquefied gas and the second liquefied gas. When heat is obtained by the heat of each gas to heat the heater 630 to the temperature required by the engine 30, the heat energy can be reduced, and the evaporated gas generated in the second liquefied gas storage tank 40 is Reliquefaction in knockout drum 640 to be described later As a result, the reliquefaction efficiency of the boil-off gas generated in the second liquefied gas storage tank 40 may be increased, and the boil-off gas generated in the first liquefied gas storage tank 20 may be cooled by the cold heat of the first liquefied gas. By reliquefaction, the reliquefaction efficiency of the boil-off gas produced in the 1st liquefied gas storage tank 20 can be increased.

The boil-off gas generated in the second liquefied gas storage tank 40 may be re-liquefied in the knockout drum 640 which will be described later, which is the second liquefied gas filled in the knockout drum 640 which will be described later. Re-liquefaction can be achieved by cooling the boil-off gas supplied into the knockout drum 640 through the second line 602 through the second liquefied gas is in the sub-cooling state through the second line (602). It is.

The heater 630 may be provided on the first line 601 between the engine 30 and the heat exchanger 620, and the same or similar components as the heater 530 of the fifth embodiment are not described herein. The description will be omitted to avoid.

The knockout drum 640 may be provided on the second line 602 to supply boil-off gas generated inside the second liquefied gas storage tank 40, and may be connected to the other end of the third line 603 to exchange heat. 620 may be configured to inject the second liquefied gas that is in the supercooled state, the same or similar components as the knockout drum 540 of the fifth embodiment will be described herein in order to avoid duplication of description. It will be omitted.

The second pump 650 may be provided on the second line 102 between the knockout drum 640 and the second liquefied gas storage tank 40, and may be the same as the second pump 550 of the fifth embodiment. As similar components, the description will be omitted here to avoid duplication of description.

The level control valve 660 may be provided at the rear end of the second pump 650 to maintain a constant level of the second liquefied gas in the knockout drum 640, the level control valve 560 of the fifth embodiment The same or similar elements as in the following description will be omitted here in order to avoid duplication of description.

The compressor 670 may be provided on the fourth line 604 between the first liquefied gas storage tank 20 and the heat exchanger 620, and is generated and discharged inside the first liquefied gas storage tank 20. Pressurized evaporated gas to be supplied to the heat exchanger (620).

8 is a conceptual diagram of a liquefied gas treatment system according to a seventh embodiment of the present invention.

As shown in FIG. 8, the liquefied gas treatment system 700 according to the seventh embodiment of the present invention may be provided in the liquefied gas carrier 1, and includes a first pump 710, a knockout drum 720, The heater 730, the second pump 740, and the level control valve 750.

In the above description, the first pump 710, the knockout drum 720, and the heater 730 may be components of a fuel supply device, and the knockout drum 720, the second pump 740, and the water level control valve 750 may be used. May be components of the reliquefaction apparatus, and the knockout drum 720 which is commonly used may be configured to link the fuel supply apparatus and the reliquefaction apparatus.

The above components may be provided on the first line 701, the second line 702, and the third line 703.

Specifically, the first line 701 may be connected from the first liquefied gas storage tank 20 to the engine 30, and heats the first liquefied gas stored in the first liquefied gas storage tank 20 to engine 30. It can be configured to be able to supply). The first pump 710, the knockout drum 720, and the heater 730 may be provided on the first line 701.

The second line 702 may have one end connected to the upper portion of the second liquefied gas storage tank 40, the other end connected to the inside of the second liquefied gas storage tank 40, and the second liquefied gas storage tank ( 40 may be configured to re-liquefy the boil-off gas generated in the interior. The knockout drum 720, the second pump 740, and the level control valve 750 may be provided on the second line 702.

The third line 703 has one end connected to the second line 702 between the second liquefied gas storage tank 40 and the second pump 740 to be described later, and the other end to the knockout drum 720 to be described later. It may be connected, and may be configured to re-liquefy the boil-off gas generated in the second liquefied gas storage tank 40.

The first pump 710 may be provided on the first line 701 between the first liquefied gas storage tank 20 and the knockout drum 720 to be described later, and may be the same as the pump 510 of the fifth embodiment. As similar components, the description will be omitted here to avoid duplication of description.

The knockout drum 720 is provided on the first line 701 and the second line 702 and the second liquefied gas storage tank 40 through the second line 701 while the first line 701 penetrates the inside thereof. The boil-off gas generated therein may be supplied, and may be configured to be injected into the second liquefied gas which is connected to the other end of the third line 703 and becomes a subcooled state. In the present embodiment, instead of directly recovering the subcooled second liquefied gas to the second liquefied gas storage tank 40, the thermal shock of the second liquefied gas storage tank 40 is injected by spraying from the knockout drum 720. To prevent it.

The first line 701 penetrating the inside of the knockout drum 720 may have various forms such as a “U” magnetic tube or a straight tube. The knockout drum 720 may function as an LNG-LPG heat exchanger when the first liquefied gas is LNG and the second liquefied gas is LPG.

The second liquefied gas filled in the knockout drum 720 is circulated through the third line 703 by a second pump 740 to be described later provided in the second line 702, and the circulated second liquefied gas is The first liquefied gas flows through the inside of the knockout drum 720 and is injected into various types of first lines 701 to exchange heat with the first liquefied gas to become a subcooled state. By cooling the boil-off gas of the second liquefied gas supplied into the knockout drum 720 through the line 702 to be liquefied, thereby increasing the liquefaction efficiency of the boil-off gas generated inside the second liquefied gas storage tank 40 In this case, the first liquefied gas is the second liquefied gas and / or the second liquefied gas storage tank 40 is injected into the knockout drum 720 and the evaporated gas supplied into the knockout drum 720 inside Heat exchange with the engine through the heater 530 to be described later ( The first liquefied gas supplied to 30 may obtain heat by the heat of the boiled gas generated from the second liquefied gas to reduce heat energy when the heater 530 is heated to a temperature required by the engine 30. .

The second liquefied gas inside the knockout drum 720 may be filled at the time of loading or using a cargo pump, a conventional reliquefaction device, and the like, and the present embodiment is not limited thereto and may be filled in the knockout drum 720 by various means. Of course, the second liquefied gas can always be filled with a certain amount.

As the second liquefied gas of the supercooled state injected into the knockout drum 720 reliquefies the boil-off gas, the pressure inside the knockout drum 720 is reduced to reduce the evaporated gas generated in the second liquefied gas storage tank 40. May be continuously drawn into free flow along the second line 702. As a result, the embodiment of the present invention may eliminate the boil-off gas supply equipment to be installed in the re-liquefaction apparatus including the blower, the compressor, and the like, as the knockout drum 720 also functions as the boil-off gas supply equipment of the reliquefaction apparatus.

The heater 730 may be provided on the first line 701 between the engine 30 and the knockout drum 720. The heater 730 is the same as or similar to the heater 530 of the fifth embodiment. The description will be omitted to avoid.

The second pump 740 may be provided on the second line 702 between the knockout drum 720 and the second liquefied gas storage tank 40, and the same or similar to the knockout drum 540 of the fifth embodiment. As a component, description thereof will be omitted here to avoid duplication of description.

The level control valve 750 is continuously increased due to the reliquefaction of the boil-off gas supplied from the second liquefied gas storage tank 40 to the second liquefied gas in the knockout drum 720, the knockout drum 720 inside It may be further provided at the rear end of the second pump 740 to maintain the second level of the liquefied gas level.

The level control valve 750 is a second line 702 between the second pump 740 and the second liquefied gas storage tank 40, specifically, the second pump 740 and the second liquefied gas storage tank 40. ) May be provided on the second line 702 downstream of the connection point of the third line 703.

The level control valve 750 is opened when the level of the second liquefied gas in the knockout drum 720 is higher than a predetermined level so that the second liquefied gas is stored in the second liquefied gas storage tank 40 through the second line 702. When it is lower than a predetermined water level and closed, the second liquefied gas may be controlled to be supplied to the knockout drum 720 through the third line 703.

9 is a conceptual diagram of a liquefied gas treatment system according to an eighth embodiment of the present invention.

9, the liquefied gas treatment system 800 according to the eighth embodiment of the present invention may be provided in the liquefied gas carrier (1), the first pump 810, a pair of knockout drum ( 820a and 820b, a heater 830, a pair of second pumps 840a and 840b, and a pair of level control valves 850a and 850b.

In the above, the first pump 810, the pair of knockout drums 820a and 820b, the heater 830 may be components of a fuel supply device, and the pair of knockout drums 820a and 820b, a pair of The second pumps 840a and 840b and the pair of level control valves 850a and 850b may be components of the reliquefaction apparatus, and a pair of knockout drums 820a and 820b which are commonly used may be connected to a fuel supply device. It may be a configuration for linking the reliquefaction apparatus.

The above components may be provided on the first line 801, the pair of second lines 802a and 802b, and the pair of third lines 803a and 803b. The first line 801 is the same as or similar to the first line 701 of the seventh embodiment, and each of the pair of second lines 802a and 802b is the same or similar to the second line 702 of the seventh embodiment. Each of the pair of third lines 803a and 803b is the same as or similar to the third line 703 of the seventh embodiment, and description thereof will be omitted herein to avoid duplication of description.

The liquefied gas treatment system 800 according to the eighth embodiment of the present invention is provided between the first pump 810 and the heater 830 as compared to the liquefied gas treatment system 700 according to the seventh embodiment of the present invention. The reliquefaction apparatus configured in the above may be different. That is, the reliquefaction apparatus of the liquefied gas treatment system 700 according to the seventh embodiment includes a knockout drum 720, a second pump 740, and a level control valve 750, whereas the liquefaction apparatus according to the eighth embodiment The reliquefaction apparatus of the gas treatment system 800 includes a pair of knockout drums 820a and 820b, a pair of second pumps 840a and 840b, and a pair of level control valves 850a and 850b.

However, the reliquefaction apparatus of the liquefied gas treatment system 800 according to the eighth embodiment includes one knockout drum 820a, one second pump 840a, and one level control valve 850a. Device, another knockout drum 820b, another second pump 840b, and another level control valve 850b to form another reliquefaction device, one reliquefaction device and the other The reliquefaction apparatus of may be arranged in series between the first pump 810 and the heater 830 and may be configured in the same manner.

A pair of knockout drums 820a and 820b, a pair of second pumps 840a and 840b, and a pair of level control valves 850a and 850b respectively constitute one such reliquefaction device and another reliquefaction device. The reliquefaction apparatus of the liquefied gas treatment system 700 according to the seventh embodiment is the same or similar to each of the knockout drum 720, the second pump 740, and the water level control valve 750. The description will be omitted to avoid this.

Each of the first pump 810 and the heater 830 of the present embodiment is also the same or similar to that of the first pump 710 and the heater 730 of the seventh embodiment. do.

In the liquefied gas treatment system 800 according to the eighth embodiment of the present invention, a reliquefaction apparatus configured between the first pump 810 and the heater 830 is provided in multiple stages, in which a plurality of second liquefaction systems are provided. The type of the second liquefied gas stored in the gas storage tank 40 may be different, and the reliquefaction apparatus may be installed for each of the plurality of second liquefied gas storage tanks 40.

If the type of the second liquefied gas is different, the boiling point of the second liquefied gas stored in the first second liquefied gas storage tank 40 is the lowest and the second liquefied gas is stored in the second liquefied gas storage tank 40 It may be advantageous to make the boiling point of the second liquefied gas higher to reliquefy the boil-off gas generated from the second liquefied gas stored in a different kind.

For example, in the plurality of second liquefied gas storage tank 40, the first second liquefied gas storage tank 40 stores ethane (C ₂ H ₆ ) having a boiling point of −89.0 ° C., and a second second liquefied gas storage tank 40. The liquefied gas storage tank 40 stores propane (C ₃ H ₈ ) having a boiling point of -42 ° C., and the third second liquefied gas storage tank 40 has butane (C ₄ H ₁₀ ) having a boiling point of -0.5 ° C. When this is stored, the reliquefaction apparatus can be installed in multiple stages as in this embodiment to re-liquefy the boil-off gas.

10 is a conceptual diagram of a liquefied gas treatment system according to a ninth embodiment of the present invention.

As shown in FIG. 10, the liquefied gas treatment system 900 according to the ninth embodiment of the present invention may be provided in the liquefied gas carrier ship 1, and includes a first pump 910 and a re-condenser. 920, knockout drum 930, heater 940, second pump 950, level control valve 960, and compressor 970.

In the above description, the first pump 910, the recondenser 920, the knockout drum 930, and the heater 940 may be components of a fuel supply device, the knockout drum 930, the second pump 950, The level control valve 960 may be components of the reliquefaction apparatus, and the knockout drum 930 which is used in common may be configured to link the fuel supply apparatus and the reliquefaction apparatus.

The above components may be provided on the first line 901, the second line 902, the third line 903, and the fourth line 904.

In the ninth embodiment of the present invention, the remaining components 901 and 902 except for the recondenser 920 provided on the first line 901 and the compressor 970 provided on the fourth line 904. , 903, 910, 930, 940, 950, 960 are the components 701, 702, 703, 710, 720, 730, 740 in the liquefied gas treatment system 700 of the seventh embodiment of the present invention described above. And 750, the description thereof will be omitted in order to avoid duplication of description, and only components different from those of the seventh exemplary embodiment of the present invention will be described.

The recondenser 920 may be provided on the first line 901 between the first pump 910 and the knockout drum 930. The recondenser 920 may be an in-line type and may be configured in various forms in addition to the in-line type.

The compressor 970 may be provided on the fourth line 904, and pressurizes the boil-off gas generated in the first liquefied gas storage tank 20 to supply it to the recondenser. Here, the fourth line 904 may have one end connected to the upper portion of the first liquefied gas storage tank 20 and the other end connected to the recondenser 920.

In the above, the recondenser 920 reliquefies the boil-off gas of the first liquefied gas supplied by the compressor 970 to be used as the fuel of the engine 30. The first liquefied gas discharged from the first liquefied gas storage tank 20 may be deprived of part of cold heat in the process of reliquefying the boil-off gas upstream of the knockout drum 930.

In the present embodiment including the recondenser 920 and the compressor 970, the amount of boil-off gas generated in the first liquefied gas storage tank 20 is large and is generated in the second liquefied gas storage tank 40. It may be suitable when the amount of boil-off gas is small.

The present invention is not limited to the first to ninth embodiments described above, and a combination of the first to ninth embodiments or at least one of the first to ninth embodiments and a known technology may be used. It may be included as another embodiment.

As described above, the present embodiment is configured such that the fuel supply device and the reliquefaction device are connected to each other, and thus, the evaporation generated in the second liquefied gas storage tank 40 using the first liquefied gas stored in the first liquefied gas storage tank 20. The reliquefaction efficiency of the gas can be improved, thereby not only simplifying the components of the reliquefaction apparatus but also reducing the energy consumption and system construction cost of the reliquefaction apparatus.

In addition, the present embodiment is configured such that the fuel supply device and the reliquefaction device is connected, so that the first liquefied gas supplied from the first liquefied gas storage tank 20 to the engine 30 is the second liquefied gas storage tank 40. Heat-exchanged with the boil-off gas generated in the fuel cell, the first liquefied gas to be used as the fuel of the engine 30 can be easily obtained from the boil-off gas to evaporate, thereby improving the efficiency of LNG fuel energy supplied to the engine 30 You can.

The present invention has been described above with reference to the embodiments of the present invention, which is merely an example, and is not intended to limit the present invention. Those skilled in the art do not depart from the essential technical details of the present embodiment. It will be appreciated that various combinations or modifications and applications which are not exemplified in the embodiments are possible in scope. Therefore, technical matters related to modifications and applications that can be easily derived from the embodiments of the present invention should be interpreted as being included in the present invention.

1: liquefied gas carrier 10: hull
20: first liquefied gas storage tank 30: engine
40: second liquefied gas storage tank 100 to 900: liquefied gas treatment system
110, 160, 210, 240, 310, 410, 510, 550, 610, 650, 710, 740, 810, 840a,
840b, 910, 950: pump
120, 220, 320, 420, 520, 620: heat exchanger
130, 230, 440, 530, 630, 730, 830, 940: heater
140: blower 150, 250, 340, 460: separator
170, 260, 350: reliquefaction unit 180: temperature control valve
270: injection nozzles 330, 450, 670, 970: compressor
430: buffer tank
540, 640, 720, 820a, 820b, 930: knockout drum
560, 660, 750, 850a, 850b, 960: level control valve
920: recondenser

Claims (7)

A heat exchanger for heat-exchanging the liquefied gas generated in the first liquefied gas and the second liquefied gas storage tank supplied from the first liquefied gas storage tank to the customer;
A separator for separating a liquid phase and a gaseous phase from the cooled boil-off gas while passing through the heat exchanger; And
It includes a buffer tank for heat-exchanging the first liquefied gas to be filled therein and the boil-off gas is gas-liquid separated in the separator,
The boil-off gas is re-liquefied while passing through the heat exchanger and the buffer tank to be recovered to the second liquefied gas storage tank, and the first liquefied gas is heated while passing through the heat exchanger and the buffer tank. Processing system. The method of claim 1,
The first liquefied gas is LNG, the second liquefied gas is LPG, the heat exchanger is an LNG-BOG (LPG) heat exchanger, the buffer tank is characterized in that to perform the LNG-BOG (LPG) heat exchanger function Liquefied gas treatment system. The method of claim 1,
The first line connected to the demand destination from the first liquefied gas storage tank is provided with a fuel supply device,
The fuel supply device,
The heat exchanger provided on the first line;
The buffer tank provided on the first line;
A pump provided on the first line between the first liquefied gas storage tank and the buffer tank to pressurize the first liquefied gas; And
And a heater provided on the first line between the heat exchanger and the demand source to heat the first liquefied gas to a temperature required by the demand destination. The method of claim 1,
A reliquefaction apparatus is provided at a second line having one end connected to an upper portion of the second liquefied gas storage tank and the other end connected to an inside of the second liquefied gas storage tank.
The reliquefaction apparatus,
The heat exchanger provided on the second line;
The buffer tank provided on the second line;
The separator provided on the second line between the heat exchanger and the buffer tank; And
And a compressor provided on the second line between the second liquefied gas storage tank and the heat exchanger to pressurize the boil-off gas. The method of claim 4, wherein
A third line having one end connected to the separator and the other end connected to the second line between the buffer tank and the second liquefied gas storage tank,
The liquefied gas processing system, characterized in that the second liquefied gas separated into the liquid phase in the separator is recovered to the second liquefied gas storage tank through the third line. The method of claim 4, wherein the second line,
The liquefied gas processing system, characterized in that penetrating through the buffer tank filled with the first liquefied gas, the second line penetrates the shell-coil type. The liquefied gas carrier ship is provided with the liquefied gas treatment system according to any one of claims 1 to 6.

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