KR20180135799A - Reliquefaction system for boil-off gas and ship having the same - Google Patents

Abstract

The present invention relates to an evaporative gas re-liquefaction system and a ship, and more particularly, to an evaporative gas re-liquefaction system and an evaporative gas re-liquefaction system, which comprises: an evaporative gas compressor for compressing evaporative gas generated in a liquefied gas storage tank into multi- An evaporative gas heat exchanger for exchanging heat between the evaporated gas compressed in the evaporative gas compressor and the evaporated gas introduced into the evaporative gas compressor; A decompression valve for decompressing the evaporated gas heat-exchanged in the evaporative gas heat exchanger after being compressed in the evaporative gas compressor; And a gas-liquid separator for gas-liquid separating the decompressed gas from the decompression valve, wherein the lubricating oil used in the gas-phase compressor of the high-pressure stage is mixed with the vaporized gas and introduced into the gas-liquid separator, And a lubricant blocking plate provided to filter out the lubricating oil between the inlet of the evaporator and the outlet of the liquid evaporating gas.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an evaporation gas re-

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an evaporation gas remelting system and a ship.

According to recent technology development, liquefied gas such as Liquefied Natural Gas and Liquefied Petroleum Gas is used as engine fuel instead of gasoline or diesel.

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 provided in a ship to be used as fuel for an engine provided in a ship. Liquefied natural gas is reduced to about 1/600 volume by liquefaction, and liquefied petroleum gas is liquefied And the storage efficiency is high.

However, since the liquefied gas is stored at a cryogenic temperature which is lowered to the boiling point and forced to liquefy, a part of the liquefied gas naturally vaporizes and changes into the evaporation gas as heat is permeated from the outside.

When the internal pressure of the liquefied gas storage tank exceeds the pressure that can be tolerated by the liquefied gas storage tank, the liquefied gas storage tank The tank may be damaged.

Therefore, conventionally, in order to keep the internal pressure of the liquefied gas storage tank constant, the evaporation gas is discharged to the outside and burned to lower the internal pressure of the liquefied gas storage tank, or the evaporation gas is liquefied And then recovered to the liquefied gas storage tank.

However, when the evaporation gas is merely discharged to the outside, there is a problem of environmental pollution. When the re-liquefying device is used, problems such as cost and manpower required for operating and providing the liquefaction device arise. Therefore, it is required to develop an effective treatment method of the evaporation gas generated by external heat penetration.

The present invention has been made in order to improve the prior art, and it is an object of the present invention to provide an evaporative gas heat exchanger and an evaporative gas heat exchanger in which when a lubricating oil used in an evaporative gas compressor is introduced into an evaporative gas heat exchanger or the like while allowing evaporation gas to be liquefied through heat exchange, An evaporation gas re-liquefaction system and a ship capable of efficiently processing lube oil.

An evaporative gas re-liquefaction system according to an embodiment of the present invention includes: an evaporative gas compressor that compresses an evaporative gas generated in a liquefied gas storage tank in multiple stages to supply it to a customer; An evaporative gas heat exchanger for exchanging heat between the evaporated gas compressed in the evaporative gas compressor and the evaporated gas introduced into the evaporative gas compressor; A decompression valve for decompressing the evaporated gas heat-exchanged in the evaporative gas heat exchanger after being compressed in the evaporative gas compressor; And a gas-liquid separator for gas-liquid separating the decompressed gas from the decompression valve, wherein the lubricating oil used in the gas-phase compressor of the high-pressure stage is mixed with the vaporized gas and introduced into the gas-liquid separator, And a lubricant blocking plate provided to filter out the lubricating oil between the inlet of the evaporator and the outlet of the liquid evaporating gas.

Specifically, the evaporative gas supply line is connected to the consumer through the evaporative gas compressor in the liquefied gas storage tank. And an evaporation gas return line branched from the evaporation gas compressor downstream from the evaporation gas compressor and connected to the liquefied gas storage tank via the evaporation gas heat exchanger, the pressure reducing valve, and the gas-liquid separator.

Specifically, the gas-liquid separator separates the decompressed evaporated gas from the decompression valve by gas-liquid separation, returns the liquid-phase evaporated gas to the liquefied gas storage tank, and transfers the vapor-phase evaporated gas to the evaporated gas heat exchanger.

Specifically, the gas-liquid separator can deliver the gas-phase evaporated gas to the evaporative gas compressor through the evaporative gas heat exchanger.

Specifically, the gas-liquid separator may further include a vapor-phase evaporation gas delivery line connected to the evaporation gas compressor via the evaporation gas heat exchanger, upstream of the evaporation gas compressor.

Specifically, the gas-liquid separator comprises: a housing; An evaporation gas inlet connected to the evaporation gas return line for introducing the evaporation gas into the housing; A liquid evaporative gas discharge unit for discharging the liquid evaporative gas inside the housing to the evaporative gas return line; A weir provided between the evaporating gas inlet and the liquid evaporating gas outlet; And the lubricant shielding plate provided below the weir to suppress the inflow of lubricant to the liquid evaporative gas exhausting unit.

Specifically, the evaporation gas inlet may be a half open inlet having a lower side opened.

Specifically, the liquid evaporative gas discharge unit discharges the liquid evaporative gas flowing in from the evaporative gas inlet unit to the upper side of the weir, or from the evaporative gas inlet unit to the lower side of the weir, It is possible to discharge a liquid vaporized gas.

Specifically, the weir is provided in a vertical direction, and the lubricant shielding plate may be provided in a horizontal direction.

Specifically, the liquid evaporative gas discharge portion may be provided at a position spaced upward from the lubricant shielding plate.

Specifically, the lubricant shielding plate may be a porous plate for suppressing the passage of lubricant.

A ship according to one aspect of the present invention is characterized by having the evaporation gas remelting system.

The evaporation gas re-liquefaction system and the ship according to the present invention can prevent the evaporation gas re-liquefaction system and the ship from leaking the evaporation gas as the lubricating oil used in the evaporation gas compressor of the high pressure stage is introduced into the evaporation gas heat exchanger, In contrast to disturbing the flow, the lubrication oil can be effectively removed to ensure the re-liquefaction efficiency.

1 is a side view of a ship having an evaporative gas remelting system according to the present invention;
2 is a conceptual diagram of a vaporization gas re-liquefaction system according to a first embodiment of the present invention.
3 is a cross-sectional view of the gas-liquid separator of the evaporative gas remelting system according to the first embodiment of the present invention.
4 is a cross-sectional view of the gas-liquid separator in the evaporative gas re-liquefaction system according to the second embodiment of the present invention.
5 is a cross-sectional view of the gas-liquid separator in the evaporative gas re-liquefaction system according to the third embodiment of the present invention.
6 is a cross-sectional view of the gas-liquid separator in the evaporative gas re-liquefaction system according to the fourth embodiment of the present invention.
7 is a conceptual diagram of a vaporization gas remelting system according to a fifth embodiment of the present invention.
8 is a conceptual diagram of a vaporization gas remelting system according to a sixth embodiment of the present invention.
9 is a conceptual diagram of a vaporization gas re-liquefaction system according to a seventh embodiment of the present invention.
10 is a conceptual diagram of an evaporative gas remelting system according to an eighth 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, ethane, or the like, which may be a Liquefied Natural Gas (LNG). In addition, the evaporation gas may refer to a boil-off gas (BOG) which is a naturally vaporized liquefied gas. It is also noted that the current state of the liquefied and evaporated gases (gas, liquid, etc.) is not limited by name. For example, the evaporation gas includes a liquid state by re-liquefaction.

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

1 is a side view of a ship having an evaporative gas remelting system according to the present invention;

Referring to FIG. 1, a ship 1 to which the evaporation gas re-liquefaction system 2 according to the present invention is applied may be a liquefied gas carrier carrying a plurality of liquefied gas storage tanks 10 in the longitudinal direction inside the ship, For example, the vessel 1 may be an LNG carrier.

The liquefied gas storage tank 10 provided in the ship of the ship 1 stores liquefied gas. The liquefied gas storage tank 10 can store the cryogenic state by liquefying the gas whose boiling point is lower than the normal temperature.

The liquefied gas storage tank 10 may be of a membrane type, a stand-alone type, a pressure vessel type, or the like, but is not particularly limited. However, in the liquefied gas storage tank 10, a part of the liquefied gas is spontaneously vaporized to generate an evaporated gas irrespective of the type of the liquefied gas, and the evaporated gas may be a problem because the internal pressure of the liquefied gas storage tank 10 is raised .

Therefore, the present embodiment can discharge the evaporated gas to the outside of the liquefied gas storage tank 10 in accordance with the internal pressure of the liquefied gas storage tank 10, and the discharged evaporated gas is re-liquefied and stored in the liquefied gas storage tank 10 Can be returned.

Alternatively, the present invention can use the evaporation gas as the fuel of the customer 3. At this time, the customer 3 may be provided in the vessel 1, and for example, the high pressure engine 3a (ME A low pressure engine 3b (DFDE power generation engine) and / or a gas combustion apparatus 3c (GCU) for covering the internal power load of the ship 1, and the like.

In the present specification, however, the customer 3 may be limited to the high-pressure consumer 3 such as the high-pressure engine 3a except for the low-pressure consumer 3 such as the low-pressure engine 3b and the gas- Of the.

The liquefied gas can also be used as the fuel for the customer 3 in addition to the evaporated gas generated in the liquefied gas storage tank 10. For this purpose, (Not shown), a heavy-carbon separator (not shown), a high-pressure pump (not shown), and the like.

A cabin (not shown), an engine casing (not shown), and the like can be provided on the upper deck of the vessel 1, and the configurations of the evaporation gas remapping system 2 can also be provided on the upper deck. However, the installation position of various components constituting the evaporation gas re-liquefaction system 2 is not particularly limited.

It is noted that the ship 1 according to the present invention is a representation covering various offshore plants such as FPSO, FSRU and the like capable of storing liquefied gas in addition to a liquefied gas carrier.

FIG. 2 is a conceptual diagram of a vaporization gas re-liquefaction system according to a first embodiment of the present invention, and FIG. 3 is a sectional view of a gas-liquid separator of the evaporation gas remover system according to the first embodiment of the present invention.

2 and 3, the evaporation gas re-liquefaction system 2 according to the first embodiment of the present invention includes an evaporation gas compressor 20, an evaporation gas heat exchanger 30, a pressure reducing valve 40, A separator 50, a lubricant treatment portion 60, and lubricant filters 70a, 70b and 70c.

The evaporation gas compressor (20) compresses the evaporation gas generated in the liquefied gas storage tank (10) in multiple stages and supplies it to the customer (3). The evaporation gas compressor 20 may be a centrifugal type, a reciprocating type, a screw type, or the like, and a plurality of the evaporation gas compressors 20 may be provided in series to compress the evaporation gas to a high pressure. The evaporative gas compressor 20 may also be provided in parallel for backup or load sharing.

The evaporative gas compressor 20 can compress the evaporated gas discharged from the liquefied gas storage tank 10 to about 1 bar to a high pressure of 200 bar or more (for example, 200 to 400 bar). For this purpose, the evaporative gas compressor 20 may be provided in five stages, for example.

The five-stage evaporative gas compressor 20 can be divided into a low-pressure evaporator gas compressor 20a and a high-pressure evaporator gas compressor 20b. The first stage to the third stage of the fifth stage may be referred to as a low-pressure stage evaporative gas compressor 20a, and the fourth stage and the fifth stage may be referred to as a high-pressure stage evaporative gas compressor 20b.

The criterion for distinguishing between the evaporator gas compressor 20a at the low pressure stage and the evaporator gas compressor 20b at the high pressure stage depends on whether or not the lubricant L is mixed into the evaporation gas. In the case of the low pressure stage evaporative gas compressor 20a, the lubricating oil L used for driving the evaporative gas compressor 20 is not introduced into the evaporative gas during the process of compressing the evaporative gas, while the evaporative gas compressor 20b The lubricating oil L used for driving the evaporative gas compressor 20 can be introduced into the evaporating gas as the evaporating gas is compressed at a high pressure.

Therefore, the evaporated gas compressed to the third stage in the fifth stage of the evaporative gas compressor 20 is not mixed with the lubricating oil L, but the evaporated gas compressed after the fourth stage is mixed with the lubricating oil L, It can be a problem. In order to solve this problem, the present invention includes various configurations described below.

An evaporation gas supply line 21 is provided from the liquefied gas storage tank 10 to the customer 3. The evaporation gas supply line 21 is provided with evaporation gas supply valves 211a and 211b and an evaporation gas compressor 20 And the evaporated gas is discharged from the liquefied gas storage tank 10 and is delivered to the customer 3 via the evaporative gas compressor 20.

However, the surplus evaporated gas can be liquefied and returned to the liquefied gas storage tank 10, and the evaporated gas can be returned to the liquefied gas storage tank 10, On the downstream side of the compressor 20, the evaporation gas return line 31 can be branched.

The evaporation gas flow from the evaporation gas supply line 21 to the evaporation gas return line 31 is supplied to the high pressure evaporation gas return valve 311 provided in the evaporation gas return line 31 and / Lt; / RTI >

A separator 22, a coalescer 23, and the like (not shown) are disposed downstream of the evaporation gas compressor 20 in the evaporation gas supply line 21 to filter out substances not required to be supplied to the liquid or the customer 3 from the evaporation gas. And a gas valve train 24 for controlling the flow rate of the evaporative gas may be provided upstream of the customer 3. [

On the upstream side of the evaporation gas compressor 20b at the high pressure stage in the evaporation gas supply line 21, the low pressure evaporation gas supply line 212 can be branched. For example, the low-pressure evaporation gas supply line 212 can be connected at the second stage downstream of the evaporation gas compressor 20a at the low-pressure stage and is connected to the low-pressure demand site 3. [

The consumer 3 connected to the evaporation gas supply line 21 may be the high pressure consumer 3 and the consumer 3 connected to the low pressure evaporation gas supply line 212 may be the low pressure consumer 3. The low pressure consumer 3 may be a power generation engine or the like and the evaporation gas supply line 21 is a main stream and the low pressure evaporation gas supply line 212 is a side stream can be referred to as a side stream.

The low-pressure consumer 3 may be a DFDE low-pressure engine 3b as shown in the figure, or a gas-fired burner 3c that burns off the evaporated gas. The pressure of the evaporative gas required by the low pressure consumer (3) may be around 10 bar.

The low-pressure evaporation gas supply line 212 is provided with a low-pressure evaporation gas supply valve 213 for controlling the flow of evaporation gas equally or similarly to the evaporation gas supply valves 211a and 211b provided in the evaporation gas supply line 21 .

The evaporation gas heat exchanger (30) exchanges heat between the evaporation gas compressed in the evaporation gas compressor (20) and the evaporation gas introduced into the evaporation gas compressor (20). The evaporation gas return line 31 described above can be branched from the evaporation gas supply line 21 downstream of the evaporation gas compressor 20 and connected to the liquefied gas storage tank 10 via the evaporation gas heat exchanger 30 and the like have. The evaporation gas supply line 21 may also be connected to the consumer 3 via the evaporation gas heat exchanger 30 and the evaporation gas compressor 20 in the liquefied gas storage tank 10 in turn.

Therefore, the evaporation gas heat exchanger 30 is connected to the evaporation gas return line 31 in parallel to the evaporation gas supply line 21 and has a flow path (not shown) through which the evaporation gas of the low pressure / (Not shown) through which the evaporation gas of the low-pressure / low-temperature gas flows (flash flow), which is in parallel with the vapor-evaporation gas delivery line 51 to be described later, (Not shown) may be provided.

The evaporation gas heat exchanger 30 is a condenser for condensing the high temperature evaporation gas introduced along the evaporation gas return line 31 after being compressed by the evaporation gas compressor 20 into the low temperature evaporation gas discharged from the liquefied gas storage tank 10 Lt; / RTI > Since the evaporation gas flowing along the evaporation gas return line 31 must be returned to the liquefied gas storage tank 10 after liquefaction, the evaporation gas heat exchanger 30 can perform precooling before liquefaction to increase liquefaction efficiency.

However, the lubricating oil L may be mixed in the evaporated gas compressed by the evaporator gas compressor 20b at the high pressure stage. The evaporated gas mixed with the lubricating oil L is mixed with the evaporated gas heat exchanger 30). ≪ / RTI >

At this time, the lubricating oil (L) is a material having a boiling point relatively higher than that of the evaporating gas, and may be in a liquid state at room temperature, may be sufficiently solidified even with a slight cooling, and may have a high viscosity.

However, if the flow in the evaporative gas heat exchanger 30 is reduced due to the absence of excess evaporative gas or the like, the evaporative gas heat exchanger 30 The lubricating oil L is caught in the oil passage of the oil separator 30 and can interfere with the flow.

Therefore, in order to solve the problem that the lubricating oil L interferes with the flow of the evaporation gas in the structures provided downstream of the evaporation gas heat exchanger 30 and the evaporation gas heat exchanger 30, So that the lubricant (L) can be melted and pushed out. This will be described later.

The present embodiment may include a secondary evaporating gas heat exchanger 32 in which the high pressure evaporating gas cooled in the evaporating gas heat exchanger 30 is discharged from the gas-liquid separator 50 It can be cooled with vapor-phase gas.

To this end, the auxiliary evaporative gas heat exchanger 32 is connected to the evaporative gas return line 31 through a flow path (not shown) connected to the evaporative gas heat exchanger 30 downstream of the evaporative gas return line 31, (Not shown) connected to the upstream of the evaporating gas heat exchanger 30 in the evaporating gas heat exchanger 30. However, the auxiliary evaporative gas heat exchanger 32 may not have a flow passage through which the evaporative gas discharged from the liquefied gas storage tank 10 is transferred to the evaporative gas compressor 20.

The auxiliary evaporation gas heat exchanger (32) can further cool the high-pressure evaporation gas cooled by the vapor-phase evaporation gas in the evaporation-gas heat exchanger (30) with vapor-phase evaporation gas. The high pressure evaporation gas compressed in the evaporation gas compressor 20 and flowing along the evaporation gas return line 31 is supplied to the evaporation gas heat exchanger 30 through the low temperature evaporation gas discharged from the liquefied gas storage tank 10 and the auxiliary After being firstly cooled by vapor-phase evaporative gas delivered from the evaporative gas heat exchanger 32, can be secondarily cooled by vapor-phase evaporative gas delivered from the gas-liquid separator 50 in the auxiliary evaporative gas heat exchanger 32.

Of course, the auxiliary evaporative gas heat exchanger 32 may be omitted, and the evaporative gas heat exchanger 30 and the auxiliary evaporative gas heat exchanger 32 may be integrally provided. That is, the evaporating gas heat exchanger 30 may include a secondary evaporating gas heat exchanger 32 inside the internal flow path structure.

The decompression valve (40) decompresses the evaporated gas heat-exchanged in the evaporation gas heat exchanger (30) after being compressed in the evaporation gas compressor (20). It is noted that the pressure reducing valve 40 in the present invention may be a line-thrombone valve, but may be replaced by various means capable of reducing the pressure, such as an inflator.

The evaporation gas is compressed to about 50 bar by the evaporator gas compressor 20a at the low pressure stage and compressed to 200 bar or more by the evaporator gas compressor 20b at the high pressure stage and then cooled in the evaporation gas heat exchanger 30. However, even if the evaporation gas is compressed to a high pressure to raise the boiling point, the evaporation gas is not sufficiently liquefied by cooling in the evaporation gas heat exchanger 30.

Therefore, the present invention can utilize the effect of decreasing the temperature during the decompression by using the pressure reducing valve (40). The decompression valve 40 can reduce the high-pressure evaporation gas of 200 bar or more to about 1 bar, which is similar to the internal pressure of the liquefied gas storage tank 10, and the temperature of the evaporation gas at the time of decompression can fall below the boiling point.

The pressure reducing valve 40 is provided on the evaporation gas return line 31. Unlike the drawing, a plurality of evaporation gas return lines 31 may be provided in series. Or deformation in which a line-thomson valve and an inflator are provided in series.

The gas-liquid separator (50) separates the vaporized gas decompressed by the pressure-reducing valve (40). The evaporation gas may be cooled by the evaporation gas heat exchanger 30 and may be liquefied while being decompressed by the pressure reducing valve 40. However, depending on the situation, complete re-liquidization may not be performed, and nitrogen such as nitrogen Some materials may remain un-liquefied.

The vaporized vapor remaining in the gaseous state may be separated from the gas-liquid separator 50 and may not flow into the liquefied gas storage tank 10, and the liquid-state vaporized gas G may be passed through the gas-liquid separator 50 Is returned to the liquefied gas storage tank (10) along the evaporated gas return line (31) connected to the liquefied gas storage tank (10). At this time, a liquid evaporative gas return valve 312 may be provided in the evaporative gas return line 31 between the gas-liquid separator 50 and the liquefied gas storage tank 10.

The gas-liquid separator 50 can return the liquid vaporized gas G to the liquefied gas storage tank 10 and deliver the vaporized gas to the vaporized gas heat exchanger 30. The vaporized vapor gas delivered to the vaporized gas heat exchanger 30 in the gas-liquid separator 50 is cooled by the reduced pressure by the pressure reducing valve 40. The vaporized gas is compressed in the vaporized gas compressor 20, Pressure evaporation gas flowing into the evaporator.

The gas-liquid separator 50 may deliver the gas-phase evaporated gas to the evaporative gas compressor 20 via the evaporative gas heat exchanger 30. The gas-liquid separator 50 is provided with a gas-phase evaporation gas delivery line 51. The gas-liquid evaporation gas delivery line 51 is connected to the vapor-liquid separator 50 via an evaporation gas heat exchanger 30, 21, and the gas-phase evaporation gas delivery line 51 may be provided with a vapor-phase evaporation gas delivery valve 511 for controlling the flow of the gas-phase evaporation gas upstream and / or downstream of the evaporation gas heat exchanger 30 have.

The point at which the vapor evaporation gas delivery line 51 is connected to the evaporation gas supply line 21 may be upstream of the evaporation gas compressor 20 so that the evaporation gas compressor 20 is discharged from the liquefied gas storage tank 10 The evaporation gas is supplied in addition to the evaporation gas, so that the efficiency can be increased as the operation is guaranteed to be more than a certain level.

As described above, the lubricating oil L used in the evaporating gas compressor 20b of the high pressure stage can be mixed with the evaporating gas, and the gas-liquid separator 50 is capable of mixing the lubricating oil L of the liquefied gas stored in the liquefied gas storage tank 10 can be prevented from being mixed to prevent deterioration of the quality of the liquefied gas stored in the liquefied gas storage tank 10.

3, the gas-liquid separator 50 includes a housing 52, an evaporation gas inlet 53, a liquid evaporation gas outlet 54, a weir 55, (56), and a lubricant drain line (57).

The housing 52 stores the evaporated gas that is depressurized by the pressure reducing valve 40. The housing 52 may be in the form of a cylinder as shown in the drawing, but is not particularly limited in the shape of the housing 52.

However, since the housing 52 should store the low-pressure / low-temperature evaporation gas liquefied by the decompression while preventing the evaporation gas from vaporizing, it may be provided with a heat insulation facility for blocking the penetration of heat from the outside.

The housing 52 may be considered to be provided on the evaporative gas return line 31 and the evaporative gas return line 31 may be provided between the evaporative gas inlet 53 and the liquid evaporative gas outlet 54, And can be connected through the internal space of the housing 52.

The evaporation gas inlet (53) allows the evaporation gas to flow into the housing (52). The evaporation gas inlet 53 may be a half open inlet provided at one end of the evaporation gas return line 31 connected to the gas-liquid separator 50 from the pressure reducing valve 40, . This is to prevent the evaporation gas from scattering when the low-pressure / low-temperature evaporation gas flows into the housing 52.

The evaporation gas inlet 53 may be provided above the liquid level of the evaporation gas stored in the housing 52, but may be lower than the upper end of the weir 55. Therefore, the evaporated gas introduced through the evaporated gas inlet 53 can be mixed with the liquid evaporated gas stored in the housing 52.

The liquid evaporative gas discharge portion 54 discharges the liquid evaporative gas G inside the housing 52. The liquid evaporative gas discharge unit 54 may be provided at one end of the evaporative gas return line 31 connected to the liquefied gas storage tank 10 in the gas-liquid separator 50.

The liquid evaporative gas discharge portion 54 may be provided below the minimum level of the evaporative gas stored in the housing 52 and may be provided above the lubricant shutoff plate 56.

The evaporated gas having a predetermined liquid level or more flows over the weir 55 out of the evaporated gas flowing into the housing 52 through the evaporated gas inlet 53. The liquid evaporated gas outlet 54 is located above the weir 55, It is possible to discharge the liquid evaporation gas G which has been poured upward to the evaporation gas return line 31. For this purpose, the liquid evaporative gas discharge unit 54 and the evaporative gas discharge unit 53 are provided on opposite sides of the weir 55.

A liquid lubricant shield plate 56 is provided in the horizontal direction below the weir 55 and can be opened between the lower side of the weir 55 and the lower surface of the housing 52. The liquid evaporative gas exhaust portion 54 is evaporated It is possible to discharge the liquid vaporized gas G that has passed upward through the lubricant shield plate 56 to the evaporated gas return line 31 after passing over the weir 55 from the gas inflow part 53.

That is, the liquid evaporative gas discharge portion 54 discharges the liquid evaporative gas G that has passed through the weir 55 without passing through the lubricant shutoff plate 56, or the liquid evaporative gas (G) can be discharged.

Since the density of the lubricating oil L in the low-pressure / low-temperature evaporating gas which is reduced in pressure by the pressure reducing valve 40 and flowing into the housing 52 is a liquid or solid state and is considerably larger than that of the evaporating gas, The lubricating oil L does not pass over the upper side of the weir 55 and sinks downward even though it is mixed and flows into the housing 52 through the evaporation gas inflow portion 53. Even if the lubricant L passes over the lower side of the weir 55 And clogged by the lubricant shield plate 56.

Therefore, unlike the evaporated gas flowing into the evaporated gas inlet 53, the lubricant L may be removed from the evaporated gas discharged to the liquid evaporated gas discharge portion 54.

The weir 55 is provided between the evaporation gas inlet 53 and the liquid evaporation gas outlet 54. The weir 55 may be provided in a vertical direction within the housing 52 and may have a shape to allow the evaporation gas to pass over the upper side of the housing 52. The weir 55 may be formed of a lubricating oil mixed with the evaporating gas L can not exceed the upper side of the weir 55.

The lubricant blocking plate 56 is provided to filter the lubricating oil L between the inflow of the evaporating gas and the discharge of the liquid evaporating gas G. Specifically, the lubricating oil blocking plate 56 is disposed below the weir 55 So that the flow of the lubricating oil L into the liquid evaporating gas discharge portion 54 is suppressed.

The lubricant shutoff plate 56 may be in the form of a perforated plate having holes smaller than the lubricant L particles so as to inhibit the passage of the lubricant L and allow passage of the liquid vapor G, The liquid evaporating gas discharge portion 54 provided above the lubricating oil blocking plate 56 may be provided at a position spaced upward from the lubricating oil blocking plate 56.

This is to prevent a part of the lubricating oil L from floating through the liquid-phase evaporated-gas discharging unit 54 when the ship 1 having the gas-liquid separator 50 is tilted by an external force or the like.

The lubricant drain line 57 discharges the lubricating oil L collected at the bottom of the housing 52 to the outside. Between the lower side of the weir 55 and the bottom of the housing 52 may be an open form (a baffle (not shown) provided with a lattice may be provided), a lubricating oil L mixed in the evaporating gas, Is naturally gathered at the bottom of the housing 52 by gravity.

However, the lubricant drain line 57 can be kept closed by a drain valve (not shown). When maintenance is required, the lubricant L is discharged to the outside to check the efficiency of removing the lubricant L .

The lubricant drain line 57 may be connected to the evaporation gas return line 31. When the filter efficiency is verified at the evaporator gas compressor 20b at the high pressure stage or when the lubricant L) is sufficiently filtered, the lubricant drain line 57 may be opened toward the evaporated gas return line 31. In this case,

The lubricating oil processing unit 60 injects the high temperature gas and pushes the lubricating oil L flowing into the evaporating gas heat exchanger 30 downstream of the evaporating gas heat exchanger 30. Liquid separator 50 and the lubricating oil L used in the evaporator gas compressor 20b of the high pressure stage may be mixed with the evaporation gas and may be introduced into the evaporation gas heat exchanger 30. However, In addition to removing the lubricating oil L by using the structure, injection of the hot gas may be used to remove the lubricating oil L from being caught in the evaporating gas heat exchanger 30. [

The lubricating oil treatment section 60 can inject a high temperature gas such as nitrogen gas of 40 degrees or more into the evaporation gas heat exchanger 30. The hot gas injected into the evaporation gas heat exchanger 30 is supplied to the evaporation gas heat exchanger 30 The lubricating oil L can be heated and discharged.

It is not likely that the lubricating oil L will remain in the evaporating gas heat exchanger 30 if the evaporating gas heat exchanger 30 has a continuous flow of the evaporating gas, but if the excess evaporating gas is not generated, (L) may remain in the evaporating gas heat exchanger (30), wherein the lubricating oil (L) is further cooled by the low temperature evaporating gas discharged from the liquefied gas storage tank (10) ) To interfere with the flow of the evaporative gas.

Therefore, in this embodiment, the high-temperature gas is injected into the evaporation gas heat exchanger 30 by using the lubricating oil processing unit 60 to heat the lubricating oil L to lower the viscosity of the lubricating oil L, It is possible to prevent the flow in the evaporation gas heat exchanger 30 from being lowered.

The lubricating oil treatment section 60 injects the hot gas into the evaporation gas return line 31 upstream of the evaporation gas heat exchanger 30 and the hot gas mixed with the lubricating oil L is supplied to the evaporation gas return line 31, And can be discharged from the downstream of the valve 40.

To this end, the lubricant treatment portion 60 includes a hot gas supply portion, a hot gas discharge portion 62, and the like. The hot gas supply part is connected to the evaporation gas return line (31) upstream of the evaporation gas heat exchanger (30) to inject the hot gas.

The injection of the hot gas may be performed while the evaporation gas is not flowing in the evaporation gas return line 31. When the evaporation gas flows into the evaporation gas return line 31, the liquefaction efficiency of the evaporation gas is lowered at the time of injecting the hot gas, and at the same time, the effect of removing the lubricating oil L may be lowered. to be.

When the high temperature gas flows into the evaporation gas heat exchanger 30 through the evaporation gas return line 31, the viscosity of the lubricating oil L remaining in the evaporation gas heat exchanger 30 may be lowered by heating, And the evaporated gas heat exchanger (30).

The hot gas injection unit 61 first supplies an inert gas (for example, nitrogen gas or the like) before injecting a high temperature gas (for example, nitrogen gas having a temperature of 40 degrees or more) to push the evaporation gas inside the evaporation gas heat exchanger 30 You can. The reason for pushing out the evaporation gas is to prevent mixing of the explosive evaporative gas with the hot gas discharged together with the lubricating oil (L) in the future.

The hot gas discharging portion 62 discharges the hot gas mixed with the lubricating oil L by branching from the upstream and / or downstream of the pressure reducing valve 40 in the evaporating gas return line 31. At this time, the lubricating oil L discharged to the outside through the hot gas can be recycled, and the hot gas can also be recycled and injected into the evaporation gas heat exchanger 30 through the hot gas injection unit 61.

For example, the lubricating oil treatment section 60 filters the lubricating oil L from the hot gas + lubricating oil L discharged from the hot gas discharging section 62, reheats the hot gas, Can be used.

In addition, since the lubricating oil treatment section 60 heats nitrogen gas or the like generated from an inert gas generator (IG generator) or a nitrogen generator, etc. commonly provided in the ship 1 and uses it as a high temperature gas, have.

The lubricating oil filters 70a, 70b and 70c filter out the lubricating oil L. [ The lubricant oil filter 70a may be provided between the pressure reducing valve 40 and the gas-liquid separator 50 in the evaporation gas return line 31. [ The lubricating oil filter 70a may be provided between the hot gas discharging portion 62 and the gas-liquid separator 50 in the evaporating gas return line 31. The lubricating oil filter 70a may be provided between the hot gas discharging portion 62 and the gas- L can be prevented from entering the liquefied gas storage tank 10 or entering the vaporized gas heat exchanger 30 through the vaporized gas delivery line 51. [

The lubricating oil filter 70a described above may be a liquid-phase filter and may be provided to remove the lubricating oil L in the liquid phase.

The lubricant oil filter 70b may be provided upstream of the evaporation gas heat exchanger 30 in the evaporation gas return line 31. [ In this case, the lubricant oil filter 70b may be a gaseous filter, and may be heated to a high pressure to remove the lubricating oil L that can be placed in the supercritical state.

The lubricating oil filter 70b provided upstream of the evaporation gas heat exchanger 30 in the evaporation gas return line 31 may be an adsorption tower capable of adsorbing the lubricating oil L or may be an adsorption tower in which the evaporation gas and the lubricating oil L A cyclone separator that separates the mixture up and down using a density difference, and the like. That is, the lubricating oil filters 70a, 70b and 70c in the present invention are not limited to the general filter type but may be a term encompassing all forms in which the lubricating oil L can be filtered out from the evaporating gas.

The lubricating oil filter 70c may be provided between the evaporating gas heat exchanger 30 and the auxiliary evaporating gas heat exchanger 32 in the evaporating gas return line 31 in which case the lubricating oil filter 70c may be a liquid phase filter .

Or the lubricant filter 70c may be a liquid phase separator provided between the evaporation gas heat exchanger 30 and the auxiliary evaporation gas heat exchanger 32 in the evaporation gas return line 31. [ The liquid phase separator has a structure for separating the evaporation gas and the lubricating oil L by density difference and has a space for accommodating the evaporation gas similarly to the above-described gas-liquid separator 50 and a partition wall (not shown) L) can be separated.

Of course, the lubricating oil filters 70a, 70b and 70c described above may be provided selectively or may be provided in combination. A vapor filter is provided upstream of the evaporation gas heat exchanger 30 and a liquid filter is provided between the evaporation gas heat exchanger 30 and the auxiliary evaporation gas heat exchanger 32 to supply the lubricating oil L) can be filtered in two steps.

Thus, in this embodiment, the gas-liquid separator 50 has a structure for filtering out the lubricating oil L. When the lubricating oil L is stuck in the evaporating gas heat exchanger 30, the hot gas is forcibly injected into the lubricating oil L L can be removed. Even if the lubricating oil L is mixed with the evaporating gas in the evaporating gas compressor 20b at the high pressure stage, the storage quality of the liquefied gas storage tank 10 can be prevented from deteriorating.

4 is a cross-sectional view of the gas-liquid separator in the evaporative gas re-liquefaction system according to the second embodiment of the present invention.

Referring to FIG. 4, the evaporation gas re-liquefaction system 2 according to the second embodiment of the present invention differs from the first embodiment in the structure of the gas-liquid separator 50. Hereinafter, the present embodiment will be described mainly with respect to the differences with respect to the first embodiment, and the description omitted will be replaced with the preceding contents. This is also true in the other embodiments below.

The gas-liquid separator 50 in the present embodiment is provided with the inlet side partition wall 531, the discharge side slope walls 541a and 541b, the baffle 58).

The inlet-side partition 531 allows the evaporation gas introduced through the evaporation-gas inlet 53 to be gathered downward without being scattered, and can be omitted when the semi-open inlet is used.

The discharge side inclined walls 541a and 541b may be provided in such a manner that two or more of them are formed in the form of v or y and the center thereof is opened for passage of the evaporation gas. The discharge side inclined walls 541a and 541b obstruct the flow when the evaporated gas exits the evaporated gas return line 31 through the liquid evaporated gas discharge portion 54 so that the lubricant L is discharged to the liquid evaporated gas discharge portion 54 and can be dropped to the bottom of the housing 52. [

The baffle 58 is provided below the evaporation gas inflow section 53 and is capable of filtering the lubricating oil L from the evaporation gas that hits the inlet side partition wall 531 and falls toward the bottom of the housing 52. The baffle 58 may then be a straightener.

5 is a cross-sectional view of the gas-liquid separator in the evaporative gas re-liquefaction system according to the third embodiment of the present invention.

5, in the third embodiment of the present invention, the gas-liquid separator 50 differs from the first embodiment in that the evaporation gas inlet 53 is disposed lower than the liquid level of the evaporation gas in the housing 52, The lubricant shielding plate 56 can be provided above the gas inlet 53. [

Therefore, in the case of this embodiment, the evaporated gas flowing into the housing 52 can be filtered while passing the lubricant shield plate 56 upward, and the evaporated gas from which the lubricant L has been removed can be filtered through the weir 55 The liquid evaporating gas can be discharged to the outside of the housing 52 through the liquid evaporating gas discharging portion 54. [

The present embodiment is characterized in that the lower side of the weir 55 is fixed to the bottom of the housing 52 so that the evaporation gas can be delivered to the liquid evaporative gas discharge portion 54 through the lubricant shield plate 56 and the weir 55, The flow of the evaporation gas may not be permitted to the lower side of the evaporator 55.

6 is a cross-sectional view of the gas-liquid separator in the evaporative gas re-liquefaction system according to the fourth embodiment of the present invention.

Referring to FIG. 6, the gas-liquid separator 50 according to the fourth embodiment of the present invention may include inlet side inclined walls 532a and 532b and a lubricant blocking plate 56.

The inlet side inclined walls 532a and 532b can cause the evaporated gas introduced above the housing 52 to be collected down through the evaporated gas inlet. The inlet side inclined walls 532a and 532b may be in the form of v or y so as to realize the funnel function and the evaporated gas conveyed to the bottom of the housing 52 by the inlet side inclined walls 532a and 532b may be vertically And then flows into the liquid evaporative gas discharge portion 54 through the lubricant shield plate 56 which is placed.

The lubricating oil blocking plate 56 may be provided in a vertical direction different from the first embodiment and may be a porous plate having holes of a size that the lubricating oil L contained in the evaporation gas can not pass through.

The evaporation gas introduced by the evaporation gas inflow section 53 is supplied to the housing 52 through the inlet side slope walls 532a and 532b after the flow direction of the evaporation gas is changed downward by the inlet side slope walls 532a and 532b As shown in FIG.

Since the lubricating oil L contained in the evaporation gas can not pass through the lubricating oil blocking plate 56, only the separated evaporating gas of the lubricating oil L passes through the evaporating gas return line 31 through the liquid evaporating gas discharging portion 54, .

7 is a conceptual diagram of a vaporization gas remelting system according to a fifth embodiment of the present invention.

Referring to FIG. 7, the evaporative gas remelting system 2 according to the fifth embodiment of the present invention further includes a vapor bypass line 33 and a vapor vapor gas bypass line 512 as compared with the previous embodiment. For reference, the valve marked in black in FIG. 7 indicates that it is in an airtight state.

The evaporative gas bypass line (33) allows the evaporated gas discharged from the liquefied gas storage tank (10) to bypass the evaporative gas heat exchanger (30) to be delivered to the evaporative gas compressor (20). The evaporation gas bypass line (33) may be provided with an evaporation gas bypass valve (331) for controlling the flow of the evaporation gas bypass line (33).

The present embodiment differs from the first embodiment in that instead of injecting a separate high temperature gas, the high temperature gas heated by the evaporation gas compressor 20 is used to heat the lubricating oil L can be heated and removed.

However, when the high temperature evaporated gas flows into the evaporated gas heat exchanger 30, and the low temperature evaporated gas discharged from the liquefied gas storage tank 10 also flows into the evaporated gas heat exchanger 30, the lubricant L) may not be properly heated or removed.

Therefore, in this embodiment, the evaporation gas bypass line 33 is provided so that the low-temperature evaporated gas discharged from the liquefied gas storage tank 10 is supplied to the evaporative gas compressor 20 without flowing into the evaporative gas heat exchanger 30 . The high-temperature evaporated gas flowing into the evaporation gas heat exchanger (30) can effectively heat and remove the lubricating oil (L).

The vapor-phase vapor bypass line 512 allows the vapor-phase evaporative gas discharged from the gas-liquid separator 50 to bypass the evaporative gas heat exchanger 30 and be delivered to the evaporative gas compressor 20. The vapor evaporation gas bypass line (512) is provided with a vapor evaporation gas bypass valve (513) for controlling the flow of the vapor evaporation gas bypass line (512).

The reason why the vapor vapor gas bypasses the vapor gas heat exchanger 30 is to achieve the same object as that of the above-mentioned low temperature vapor gas bypassing the vapor gas heat exchanger 30. [ As a result, the high-temperature evaporated gas discharged from the evaporated gas compressor 20 is not cooled by the low-temperature evaporated gas or the vaporized evaporated gas in the evaporated gas heat exchanger 30, so that the lubricating oil L can be sufficiently heated.

That is, in this embodiment, the high-pressure evaporation gas return valve 311 is opened to transfer the high-temperature evaporation gas heated in the evaporation gas compressor 20 to the evaporation gas heat exchanger 30, at which time the evaporation gas supply valve 211a is closed The evaporation gas bypass valve 331 may be opened to prevent the low temperature evaporated gas discharged from the liquefied gas storage tank 10 from cooling the high temperature evaporated gas.

The gas phase evaporation gas transfer valve 511 is closed and the vapor phase gas bypass valve 513 is opened so that the vapor phase gas discharged from the gas-liquid separator 50 is not introduced into the vapor phase gas heat exchanger 30, The evaporated gas heat exchanger 30 may be bypassed along the heat exchanger 512 so that the gaseous evaporated gas does not cool the hot evaporated gas.

Therefore, the present embodiment can effectively remove the lubricating oil L caught in the evaporation gas heat exchanger 30 by using the high-temperature evaporation gas.

8 is a conceptual diagram of a vaporization gas remelting system according to a sixth embodiment of the present invention.

Referring to FIG. 8, the evaporation gas remelting system 2 according to the sixth embodiment of the present invention may further include a high-temperature evaporation gas supply line 514 as compared with the fifth embodiment, Line 512 may be omitted. For reference, the valve shown in black in FIG. 8 indicates that it is in the closed state.

The high-temperature evaporation gas supply line 514 is connected to the evaporation gas heat exchanger 30 (in this embodiment, the evaporation gas heat exchanger 30) The high-temperature evaporated gas discharged from the evaporating-gas heat exchanger 30 can be delivered to the customer 3. [0050]

The high temperature evaporation gas supply line 514 may be branched from the upstream side of the pressure reducing valve 40 in the evaporation gas return line 31 and connected to the upstream side of the customer 3 in the evaporation gas supply line 21. That is, in this embodiment, unlike the previous embodiment, the high temperature evaporation gas can be taken out from the evaporation gas return line 31 at a high pressure state.

The high temperature evaporated gas mixed with the lubricating oil L while being heated by the evaporating gas heat exchanger 30 by heating the lubricating oil L can be delivered to the consumer 3 and consumed. Therefore, in this embodiment, the lubricating oil L removed from the evaporation gas heat exchanger 30 is not recirculated, so that the lubricating oil L is prevented from flowing into the liquefied gas storage tank 10.

The high pressure evaporation gas return valve 311 may be provided between the point where the evaporation gas return line 31 is branched in the evaporation gas supply line 21 and the point where the high temperature evaporation gas supply line 514 is connected When the high-pressure evaporation gas return valve 311 is closed, the high-temperature evaporation gas compressed by the evaporation gas compressor 20 flows into the evaporation gas heat exchanger 30 along the evaporation gas return line 31.

The low temperature evaporation gas discharged from the liquefied gas storage tank 10 flows through the evaporation gas bypass line 33 as the evaporation gas supply valve 211a is closed and the evaporation gas bypass valve 331 is opened, Do not cool.

The high temperature evaporated gas from which the lubricating oil L has been removed from the evaporation gas heat exchanger 30 flows along the high temperature evaporation gas supply line 514 as the pressure reducing valve 40 is closed and flows through the evaporation gas supply line 21 To the customer (3).

In this case, since the high-temperature evaporation gas does not flow into the gas-liquid separator 50, the vapor-phase evaporation gas may not be generated, and the vapor-phase evaporation gas delivery valve 511 may be closed. Therefore, the high temperature evaporated gas introduced into the evaporation gas heat exchanger 30 can sufficiently heat the lubricating oil L.

9 is a conceptual diagram of a vaporization gas re-liquefaction system according to a seventh embodiment of the present invention.

9, the evaporation gas re-liquefaction system 2 according to the seventh embodiment of the present invention is a system in which the high-pressure / high-temperature evaporation gas compressed in the evaporation gas compressor 20b at the high pressure stage It is possible to utilize the compressed low-pressure / high-temperature evaporating gas in the evaporating-gas compressor 20a at the low-pressure stage.

For this purpose, in place of the vapor evaporation gas bypass line 512 of the fifth embodiment described above or the high-temperature evaporation gas supply line 514 of the sixth embodiment described above, the low-pressure evaporation gas supply line 212 A low pressure evaporation gas return line 214 may be provided which branches the high pressure evaporation gas return line 214 and transfers the high temperature evaporation gas (about 43 degrees to about 40 degrees) to the evaporation gas heat exchanger 30, A low pressure evaporative gas return valve 215 is provided to control the flow of the gas return line 214.

The low-pressure evaporation gas return line 214 is a line for returning the high-temperature evaporation gas compressed in the evaporation gas compressor 20a of the low-pressure stage to the evaporation gas heat exchanger 30 ). ≪ / RTI >

The low pressure evaporation gas return line 214 is branched at the low pressure evaporation gas supply line 212 and connected to the evaporation gas return line 31 upstream of the evaporation gas heat exchanger 30. Therefore, in order to remove the lubricating oil L of the evaporation gas heat exchanger 30, this embodiment locks the high-pressure evaporation gas return valve 311 provided in the evaporation gas return line 31 and the low-pressure evaporation gas return valve 215 And the high-temperature evaporated gas compressed by the evaporator gas compressor 20a at the low-pressure stage can be transferred to the evaporator gas heat exchanger 30. [

At this time, the high temperature evaporated gas flowing into the evaporated gas heat exchanger (30) is not cooled by the low temperature evaporated gas discharged from the liquefied gas storage tank (10) as described in the other embodiments.

In this embodiment, the high-temperature evaporation gas may not be heat-exchanged with the vapor-phase evaporation gas discharged from the gas-liquid separator 50. For this purpose, the present embodiment may further include the high-temperature evaporation gas transmission line 515, The evaporation gas delivery line 515 may include a high temperature evaporation gas delivery valve 516.

The hot evaporation gas delivery line 515 may be connected to the low pressure consumer 3 in the gas-liquid separator 50. For example, the hot evaporation gas delivery line 515 may be connected to the evaporation gas heat exchanger 30 in the gas- Or may be branched from the vapor vapor gas delivery line 51 connected to the vapor gas compressor 20 and connected to the low pressure consumer 3 or the low pressure vapor gas supply line 212.

The high temperature evaporated gas compressed in the evaporator gas compressor 20a at the low pressure stage is transferred to the evaporation gas return line 31 and flows into the evaporation gas heat exchanger 30 as the low pressure evaporation gas return valve 215 is opened. At this time, the low-pressure evaporation gas supply valve 213 provided in the low-pressure evaporation gas supply line 212 may be sealed.

The low-pressure / high-temperature evaporation gas introduced into the evaporation-gas heat exchanger 30 can be heated by pushing the lubricating oil L interposed in the evaporation-gas heat exchanger 30, Liquid separator 50 as shown in FIG. However, since the high temperature evaporation gas used to remove the lubricating oil L is low pressure, the temperature decrease does not occur even if the pressure is reduced by the pressure reducing valve 40 (for example, when the pressure is reduced from 10 bar to 7 bar, Lt; / RTI >

The high-temperature vaporized gaseous state introduced into the gas-liquid separator 50 is then supplied to the gas-liquid separator 50 through the gas-liquid evaporation-gas transfer line 515, The gas can be supplied to the DFDE low-pressure engine 3b and / or the gas combustion device 3c and the like, which are the low-pressure customer 3, along the high-temperature evaporation gas delivery line 515 as the high-temperature evaporation gas delivery valve 516 is opened .

The high-temperature evaporation gas delivery line 515 is connected to the downstream of the low-pressure evaporation gas supply valve 213 provided in the low-pressure evaporation gas supply line 212 so that the high- To the low-pressure consumer 3.

As described above, in this embodiment, the high temperature evaporation gas (lubricating oil L not mixed) compressed in the evaporation gas compressor 20a at the low pressure stage is utilized for removing the lubricating oil L of the evaporation gas heat exchanger 30, L) is consumed in the low-pressure consumer 3, so that the lubricating oil L remaining in the evaporation gas heat exchanger 30 can be effectively removed.

10 is a conceptual diagram of an evaporative gas remelting system according to an eighth embodiment of the present invention.

10, the evaporation gas re-liquefaction system 2 according to the eighth embodiment of the present invention differs from the seventh embodiment in that the low-pressure / high-temperature evaporation gas The high pressure / high temperature evaporation gas compressed in the evaporation gas compressor 20b of the high pressure stage can be used for the removal of the lubricating oil (L).

In this case, the present embodiment can omit the low-pressure evaporation gas return line 214, and when the high-pressure evaporation gas return valve 311 is opened, the high-pressure / high-temperature evaporation gas flows along the evaporation gas return line 31 to the evaporation gas heat exchanger (Not shown).

The high temperature evaporated gas discharged from the evaporation gas heat exchanger 30 may be decompressed and cooled through the pressure reducing valve 40. For example, when the pressure is reduced from 300 bar to 7 bar, Can be cooled.

The high-temperature evaporated gas passed through the pressure reducing valve (40) flows into the gas-liquid separator (50). At this time, the vapor-phase evaporation gas in the high-temperature evaporation gas flows into the low-pressure consumer 3 along the high-temperature evaporation gas delivery line 515 when the vapor evaporation gas delivery valve 511 is closed and the high-temperature evaporation gas delivery valve 516 is opened Can be supplied.

However, unlike the previous embodiment, in this embodiment, since the high-temperature evaporation gas used for removing the lubricating oil L is a high pressure, the temperature decreases considerably during the decompression by the pressure-reducing valve 40.

Therefore, the high-temperature evaporated gas delivered to the low-pressure consumer 3 may not meet the required temperature of the low-pressure consumer 3. In this embodiment, the gas heater 517 may be provided in the high- have.

The gas heater 517 is compressed in the evaporation gas compressor 20b at the high pressure stage and can heat the evaporation gas passing through the evaporation gas heat exchanger 30 and the pressure reducing valve 40 to be transferred to the low pressure consumer 3, The gas heater 517 can heat the high-temperature evaporated gas cooled at about -37 ° C to about 40 ° C through the pressure reducing valve 40. Of course, the heat source used by the gas heater 517 is not particularly limited.

As described above, in this embodiment, the lubricating oil L held in the evaporation gas heat exchanger 30 or the like is heated using the high-pressure / high-temperature evaporation gas, and then the lubricating oil L can be strongly removed and effectively removed, It is possible to prevent the inflow of the lubricating oil L into the liquefied gas storage tank 10 by consuming the evaporated gas in the low pressure consumer 3.

It is needless to say that the present invention is not limited to the above-described embodiments, and that a combination of the above embodiments or a combination of at least any of the above-described embodiments with known techniques can be included as another embodiment.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be apparent to those skilled in the art that various combinations and modifications may be made without departing from the scope of the present invention. Therefore, it should be understood that the technical contents related to the modifications and applications that can be easily derived from the embodiments of the present invention are included in the present invention.

1: Ship 2: Evaporative gas re-liquefaction system
3: Demand point 3a: High-pressure engine
3b: Low pressure engine 3c: Gas combustion device
L: Lubricating oil G: Liquid vaporizing gas
10: Liquefied gas storage tank 20: Evaporative gas compressor
20a: Evaporative gas compressor of low pressure stage 20b: Evaporative gas compressor of high pressure stage
21: Evaporative gas supply lines 211a and 211b: Evaporative gas supply valves
212: low pressure evaporation gas supply line 213: low pressure evaporation gas supply valve
214: low pressure evaporation gas return line 215: low pressure evaporation gas return valve
22: separator 23: core cylinder
24: Gas valve train 30: Evaporative gas heat exchanger
31: Evaporative gas return line 311: High pressure evaporative gas return valve
312: liquid evaporative gas return valve 32: auxiliary evaporative gas heat exchanger
33: Evaporative gas bypass line 331: Evaporative gas bypass valve
40: Reducing valve 50: Gas-liquid separator
51: vapor vapor gas delivery line 511: vapor vapor gas delivery valve
512: vapor-phase evaporation gas bypass line 513: vapor-phase gas bypass valve
514: high temperature evaporation gas supply line 515: high temperature evaporation gas transmission line
516: high temperature evaporation gas delivery valve 517: gas heater
52: housing 53: evaporation gas inlet
531: inlet side partition walls 532a, 532b: inlet side inclined wall
54: liquid vaporized gas discharge portion 541a, 541b: discharge side inclined wall
55: Weir 56: Lubricant shield plate
57: Lubricating oil drain line 58: Baffle
60: lubricating oil processing part 61: high temperature gas injection part
62: high temperature gas discharging portion 70a, 70b, 70c: lubricating oil filter

Claims (12)

An evaporative gas compressor for compressing the evaporated gas generated in the liquefied gas storage tank in multiple stages and supplying the same to a customer;
An evaporative gas heat exchanger for exchanging heat between the evaporated gas compressed in the evaporative gas compressor and the evaporated gas introduced into the evaporative gas compressor;
A decompression valve for decompressing the evaporated gas heat-exchanged in the evaporative gas heat exchanger after being compressed in the evaporative gas compressor; And
And a gas-liquid separator for gas-liquid separating the decompressed gas from the decompression valve,
The lubricating oil used in the evaporation gas compressor of the high pressure stage is mixed with the evaporation gas and introduced into the gas-liquid separator,
The gas-
And a lubricant blocking plate provided to filter lubricant between the inlet of the evaporating gas and the outlet of the liquid evaporating gas. The method according to claim 1,
An evaporation gas supply line connected to the demanding place of the liquefied gas storage tank via the evaporative gas compressor; And
And an evaporative gas return line branched from the evaporative gas supply line downstream from the evaporative gas compressor and connected to the liquefied gas storage tank via the evaporative gas heat exchanger, the pressure reducing valve, and the gas-liquid separator. Evaporative gas remelting system. The gas-liquid separator according to claim 2,
Wherein the vaporized gas is separated by gas-liquid separation from the decompression valve to return the liquid vaporized gas to the liquefied gas storage tank, and the vaporized gas is transferred to the vaporized gas heat exchanger. 4. The gas-liquid separator according to claim 3,
Wherein the vaporized gas is passed through the evaporation gas heat exchanger to the evaporation gas compressor. 5. The method of claim 4,
Further comprising a gas-phase evaporation gas delivery line connected to the evaporation gas compressor upstream of the evaporation gas supply line via the evaporation gas heat exchanger in the gas-liquid separator. The gas-liquid separator according to claim 2,
housing;
An evaporation gas inlet connected to the evaporation gas return line for introducing the evaporation gas into the housing;
A liquid evaporative gas discharge unit for discharging the liquid evaporative gas inside the housing to the evaporative gas return line;
A weir provided between the evaporating gas inlet and the liquid evaporating gas outlet; And
And a lubricating oil blocking plate provided below the weir for suppressing the inflow of lubricating oil into the liquid evaporating gas discharging portion. 7. The apparatus according to claim 6, wherein the evaporation gas inlet comprises:
And a half opened inlet having a lower side opened. [7] The apparatus according to claim 6,
And discharging the liquid evaporating gas flowing into the weir from the evaporating gas inflow part or discharging the liquid evaporating gas passing through the lubricant blocking plate after passing through the weir in the inflow gas inflow part. The evaporation gas re-liquefaction system. The method according to claim 6,
The weir is provided in a vertical direction,
Wherein the lubricant shielding plate is provided in a horizontal direction. 10. The apparatus according to claim 9,
Wherein the lubricant shielding plate is provided at a position spaced upward from the lubricant shielding plate. 7. The lubricating oil filter according to claim 6,
Wherein the gas is a perforated plate for inhibiting the passage of lubricating oil. A ship characterized by having the evaporation gas remelting system according to any one of claims 1 to 11.

Images