WO2020159317A1

WO2020159317A1 - Gas processing system and ship including same

Info

Publication number: WO2020159317A1
Application number: PCT/KR2020/001535
Authority: WO
Inventors: 김현석; 권혁장; 노재욱; 노일용; 백성훈; 서석용; 손재욱; 안국진; 오민석; 오석우; 유지헌; 이근보; 이동진; 이상봉; 이병주; 이태우; 임지윤; 정상욱; 한범우; 한상호
Original assignee: 현대중공업 주식회사; 한국조선해양 주식회사
Priority date: 2019-02-01
Filing date: 2020-01-31
Publication date: 2020-08-06

Abstract

The present invention relates to a gas processing system and a ship including same, the gas processing system comprising: a storage tank for storing a liquefied gas; a propulsion engine using the liquefied gas as a fuel; a fuel supply line for supplying the liquefied gas in the storage tank to the propulsion engine; and a fuel collection line for collecting excess liquefied gas discharged from the propulsion engine, wherein: a high-pressure pump and a heat exchanger are provided in the fuel supply line, the heat exchanger being provided upstream of the high-pressure pump so as to change the temperature of the liquefied gas; and the heat exchanger performs heat exchange between the liquefied gas supplied from the storage tank to the propulsion engine and the liquefied gas collected through the fuel collection line.

Description

Gas treatment systems and vessels containing same

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

In general, liquefied petroleum gas, that is, LPG (Liquefied petroleum gas) is a liquefied by pressurizing the gas at room temperature as a main component of hydrocarbons having a low boiling point, such as propane and butane. The liquefied petroleum gas is filled into a small, lightweight pressure vessel (cylinder), and is widely used as fuel for household, business, industrial, and automobile applications.

Liquefied petroleum gas is extracted in gaseous form at the production site, liquefied and stored through a liquefied petroleum gas treatment facility, and then transported to the land while maintaining the liquid phase by the liquefied petroleum gas carrier, and then supplied to customers in various forms such as gas do.

Since the boiling point of such liquefied petroleum gas is about -50°C, the liquefied petroleum gas carrier for transporting liquefied petroleum gas must maintain a temperature lower than this. Therefore, the storage tank for storing liquefied petroleum gas uses low temperature carbon steel and nickel steel resistant to low temperature, and a reliquefaction facility is also provided on the liquefied petroleum gas carrier.

Such a liquefied petroleum gas carrier has generated propulsion by operating an engine using diesel oil in the conventional case. However, diesel oil generates nitrogen oxides (NOx), sulfur oxides (SOx), and carbon dioxide (CO2), which are harmful components in the process of combustion in a ship-propelled engine, and these harmful components are released into the atmosphere, thereby contaminating the environment. have.

Therefore, in recent years, the development of engines using liquefied petroleum gas and the development of various systems that supply liquefied petroleum gas to the engine have been continuously conducted to significantly reduce the pollution level of exhaust when compared with the case of using diesel oil. have.

The present invention was created to solve the problems of the prior art as described above, and an object of the present invention is to provide a gas treatment system capable of generating propulsion using liquefied petroleum gas and a ship including the same.

Gas processing system according to an aspect of the present invention, a storage tank for storing liquefied gas; Propulsion engine using liquefied petroleum gas as fuel; A fuel supply line for supplying liquefied gas from the storage tank to the propulsion engine; And a fuel recovery line for recovering excess liquid liquefied gas discharged from the propulsion engine, wherein the fuel supply line is provided with a high pressure pump and a heat exchanger provided upstream of the high pressure pump to change the temperature of the liquefied gas. , The heat exchanger has a gas processing system characterized by exchanging liquefied gas supplied from the storage tank to the propulsion engine and liquefied gas recovered from the fuel recovery line.

Specifically, the heat exchanger may be a three-stream structure having a stream through which liquefied gas supplied from the storage tank to the propulsion engine flows, a stream through which liquefied gas recovered from the fuel recovery line flows, and a stream through which heat exchange medium flows. have.

Specifically, the fuel recovery line delivers liquid liquefied gas to the high pressure pump, and the heat exchanger cools the liquefied gas of the fuel recovery line with liquefied gas and a heat exchange medium supplied to the propulsion engine to the high pressure pump. It can be brought into the liquid phase.

Specifically, the fuel recovery line is provided with a pressure reducing valve for depressurizing the liquid liquefied gas, and the heat exchanger may cool the decompressed liquefied gas to flow into the high pressure pump as a liquid.

Specifically, in the fuel recovery line, a mixer that is provided between the heat exchanger and the high pressure pump, and mixes liquefied gas passing through the heat exchanger and liquefied gas supplied from the storage tank and delivers it to the high pressure pump. have.

The gas treatment system according to the present invention and a ship including the same can move beyond the conventional system using only diesel oil, so that liquefied petroleum gas can be used as a propulsive fuel to reduce environmental pollution and increase energy efficiency.

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

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

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

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

5 is a conceptual diagram of a gas processing system according to a fifth embodiment of the present invention.

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

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

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

9 is a conceptual diagram of a gas processing system according to a ninth embodiment of the present invention.

10 is a conceptual diagram of a gas processing system according to a tenth embodiment of the present invention.

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

12 is a partial side view of a vessel to which a gas treatment system according to a twelfth embodiment of the present invention is applied.

13 is a partial plan view of a ship to which a gas treatment system according to a twelfth embodiment of the present invention is applied.

14 is a central sectional view of a vessel to which a gas treatment system according to a thirteenth embodiment of the present invention is applied.

15 is a plan view of a ship to which a gas treatment system according to a 14th embodiment of the present invention is applied.

16 is a conceptual view of a vessel to which a gas processing system according to a fifteenth embodiment of the present invention is applied.

17 is a front sectional view of a vessel to which a gas treatment system according to a fifteenth embodiment of the present invention is applied.

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

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. For reference, the liquefied gas may be LPG in the present specification, but is not limited thereto, and the boiling point is lower than room temperature, forcibly liquefied for storage, and may cover all substances having a calorific value.

Also, in this specification, liquefied gas/evaporation gas is classified based on the state in the tank, and it is noted that the name is not necessarily limited to liquid or gaseous phases.

The present invention includes a ship 100 equipped with a gas treatment system 1 described below. At this time, the ship 100 is a concept including a gas carrier, a merchant ship carrying cargo or people other than gas, FSRU, FPSO, Bunkering vessel, offshore plant, etc., but it is noted that it may be a liquefied petroleum gas carrier as an example. .

In the drawings of the present invention, PT is a pressure sensor, TT is a temperature sensor, and the measured value by each sensor can be used in various ways without limitation in the operation of the components described below.

Referring to FIG. 1, the gas processing system 1 according to the first embodiment of the present invention includes a fuel storage unit 10, a fuel supply unit 20, a fuel recovery unit 30, and a reliquefaction unit 40. do.

The fuel storage unit 10 stores a liquefied gas mainly composed of heavy hydrocarbons. Here, the liquefied gas may be LPG or the like described above, butane, propane, propylene, ethylene, and the like, but is not limited thereto.

The fuel storage unit 10 may be a plurality of cargo tanks 11 provided on board the ship 100 when the ship 100 is a gas carrier, and separately when the ship 100 is a ship other than a gas carrier It may be a provided tank or container.

The cargo tank 11 is a tank that stores liquefied gas in a low-temperature liquid at atmospheric pressure, and various insulating structures may be added to the wall to prevent vaporization of the liquefied gas. In addition, the cargo tank 11 may be a membrane-type tank or a stand-alone tank, and the shape and specifications are not limited.

The fuel storage unit 10 has a transfer pump 111 that discharges liquefied gas and delivers it to the fuel supply unit 20. The transfer pump 111 may be provided inside the cargo tank 11 and may be provided in a submerged type submerged in liquefied gas.

However, the transfer pump 111 may be provided only in a part of the plurality of cargo tanks 11. The cargo tank 11 is basically for cargo transportation, and the cargo pump 111a (unloading pump, stripping pump, etc., not shown) for unloading cargo is weak for each cargo tank 11. Two are provided, and at least one of the cargo tanks 11 is used to use liquefied gas stored therein as fuel such as a propulsion engine (E) (ME-LGI) or a power generation engine (DFDE, not shown), In addition to the cargo pump 111a, the transfer pump 111 may be added.

For example, when there are four cargo tanks 11, the liquefied gas stored in the cargo tank 11 no. 4 close to the engine room in which the propulsion engine E is accommodated may be used as fuel for the propulsion engine E, for this purpose 4 The transfer pump 111 may be provided only in the cargo tank 11.

A plurality of cargo tanks 11 included in the fuel storage unit 10 include a vapor main line (VM) for delivering gaseous liquefied gas and a liquid main line (LM) for delivering liquid liquefied gas (liquid) main) may be provided. At this time, the gaseous main line VM and the liquid main line LM may be provided to connect at least two or more of the cargo tanks 11 to each other.

For reference, the main lines (VM, LM) are connected to lines passing through the dome 115 provided in the cargo tank 11, and the lines passing through the dome 115 discharge/recover liquefied gas or evaporation gas. It can be a line. Therefore, the flow direction in the main lines (VM, LM) is not limited to that shown in the drawings, and the direction from the inside of the cargo tank 11 to the outside or the direction from the outside of the cargo tank 11 to the inside is possible. Do.

The plurality of cargo tanks 11 may be divided into at least two groups. For example, when four cargo tanks 11 are provided on board, the cargo tanks 11 are divided into two groups.

Groups may be classified according to the connection of the main lines (VM, LM), for example, the first group, the second to belong to at least two cargo tanks (11a) connected to each other by the first main line (VM, LM), the second At least two cargo tanks 11b connected to each other by the main lines VM and LM may belong to a second group.

The first main line (VM, LM) connecting the cargo tanks (11a) of the first group to each other, the first gaseous main line (VM1) to integrate the gaseous liquefied gas between the plurality of cargo tanks (11a), a plurality of cargo It includes a first liquid main line (LM1) for integrating the liquid liquefied gas between the tank (11a).

Of course, the second main line (VM, LM), as well as the first main line (VM, LM), the second gas phase main line to integrate the gaseous liquefied gas or liquid liquefied gas of the cargo tanks (11b) belonging to the second group (VM2) and a second liquid main line LM2.

The liquefied gas stored in the cargo tank 11 may not be used for the propulsion engine E depending on the composition. For example, when the liquefied gas is propane or butane, propulsion can be obtained by being supplied to the propulsion engine (E) through the fuel supply unit (20) through the transfer pump (111), but when the liquefied gas is propylene, the propulsion engine currently developed With (E), consumption is impossible or undesirable.

As described above, the four cargo tanks 11 may be divided into two different groups, and the first group and the second group store the same type of liquefied gas, or the first group without the transfer pump 111. The cargo tanks 11a store inadequate liquefied gas as fuel for the propulsion engine E, and the second group of cargo tanks 11b including the cargo tank 11b provided with the transfer pump 111 is the propulsion engine E In some cases, liquefied gas suitable for fuel may be stored.

However, as described above, only the fourth cargo tank 11 is used exclusively for fuel. In this case, the fourth cargo tank 11 is connected to the main line (VM, LM) or the fuel supply unit 20 in the group to which it belongs. When a problem occurs, a problem occurs that propulsion by liquefied gas becomes impossible.

That is, since the main lines (VM, LM) communicating the cargo tanks 11 with each other are divided into at least two groups, and the cargo tank 11 for using liquefied gas as fuel belongs to only one group. , There is a burden that the flow through the main lines (VM, LM) allocated to the fuel-only cargo tank 11 should always be guaranteed.

In order to improve this embodiment, a plurality of transfer pumps 111 are installed in the fourth cargo tank 11 dedicated to fuel, and the transfer pumps 111 are provided with a first main line (VM, LM) and a second main. It may be provided to be connected to the lines (VM, LM), respectively.

Specifically, any one of the transfer pump 111 is connected to the main line (VM, LM) (for example, the second liquid main line (LM2)) that is assigned to the group to which the cargo tank 11 dedicated to fuel belongs, while the other One transfer pump 111 may be connected to the main line (VM, LM) (for example, the first liquid main line LM1) assigned to another group to which the cargo tank 11 dedicated to fuel does not belong.

Therefore, in the present embodiment, the cargo tank 11 used exclusively for fuel is not connected only to the main lines VM and LM allocated to any one group, but is connected to all groups, thereby allowing one cargo tank ( 11) can be used to supply fuel through a plurality of groups. That is, different groups can be provided with a structure that backs up the fuel supply to each other.

In addition, as the cargo tank 11 dedicated to fuel is provided to be connected to the main lines VM and LM allocated to two or more groups, the cargo loading operation method can also be expanded as follows.

그룹group	기본basic	본 발명The present invention
1One	1, 3번 카고탱크 Cargo Tank 1 and 3	1, 3번 카고탱크 Cargo Tank 1 and 3	1, 3, 4번 카고탱크 Cargo tanks 1, 3 and 4
22	2, 4번 카고탱크Cargo Tank 2 and 4	2, 4번 카고탱크Cargo Tank 2 and 4	2번 카고탱크Cargo Tank 2

That is, in the present embodiment, the cargo tank 11 having the transfer pump 111 belongs to the same group as below, and it is possible to store the same or different liquefied gas from the cargo tank 11 without the transfer pump 111. For reference, P means propylene and B means butane.

	카고탱크(11)Cargo Tank(11)
	1번no. 1	2번No.2	3번number 3	4번Number 4
기본basic	PP	PP	PP	PP
	BB	BB	BB	BB
	PP	BB	PP	BB
	BB	PP	BB	PP
본 발명The present invention	BB	PP	BB	BB
본 발명The present invention	PP	BB	PP	PP

That is, the fuel storage unit 10 of the present embodiment is further provided with a cargo tank 11 that is divided into two groups and a fuel-only cargo tank 11 belonging to any one group, and furthermore, a fuel-only cargo tank 11 By having a structure that is also connected to the main lines (VM, LM) allocated to other groups, it is possible to ensure that there is no interruption in fuel supply even if a problem occurs in the delivery of liquefied gas by any one group.

The fuel supply unit 20 supplies the liquefied gas of the fuel storage unit 10 to the propulsion engine E of the ship 100 in a liquid state, and for this purpose, the fuel supply unit 20 propels from the main lines (VM, LM) It has a fuel supply line (L20) connected to the engine (E). In general, in the case of LNG, since it must be supplied in the gas phase to the engine, LNG is vaporized by heating and then supplied to the engine, but in the present invention, the fuel supply unit 20 supplies LPG or the like to the propulsion engine E in a liquid state.

At this time, the propulsion engine (E) may be an LPG engine such as ME-LGI developed by MAN, but is not limited thereto and may include all engine products that can consume LPG.

However, the state of the liquid liquefied gas that the fuel supply unit 20 pressurizes and supplies to the propulsion engine E is specifically at a critical pressure (hereinafter, the critical pressure is not a critical pressure inherent to the liquefied gas, but is at room temperature (over 20 degrees Celsius). Note that it may be an expression that means a pressure that does not vaporize at .) It may be a supercooled state that is above and below a critical temperature. That is, in the present specification, the liquid phase may be an expression encompassing supercooling.

The fuel supply unit 20, the temperature (for example, 20 to 50 degrees Celsius) and pressure (eg, 20, for example) required of the liquefied gas delivered through the transfer pump 111 provided in the cargo tank 11 in the propulsion engine E It can be supplied to the propulsion engine (E) according to the (60 ~ 60bar), of course, at least a portion of the liquefied gas from the upstream of the propulsion engine (E) can be supplied to other demand sources, such as power generation engine, boiler (B).

In this case, the conditions of the liquefied gas required by the power generation engine or the like may be different from that of the propulsion engine E. The fuel supply unit 20 may additionally adjust the temperature or pressure of the liquefied gas branched to the power generation engine or the like. It goes without saying that any means can be added.

The fuel supply unit 20 includes a heat exchanger 22, a high pressure pump 21, and a filter 23 provided on the fuel supply line L20.

The heat exchanger 22 changes the temperature of the liquefied gas. Since the heat exchanger 22 may raise or lower the temperature of the liquefied gas, it may be referred to as a fuel conditioner.

For example, during the initial operation of the present embodiment, since the flow rate of the high temperature liquefied gas recovered by the fuel recovery unit 30 to be described later is large, the heat exchanger 22 can lower the temperature of the liquefied gas, and enters stable operation In this case, the heat exchanger 22 may increase the temperature of the liquefied gas.

In addition, the heat exchanger 22 may adjust the temperature of the liquefied gas to a boiling point or less of the liquefied gas so that gaseous liquefied gas does not flow into the high pressure pump 21 provided downstream of the heat exchanger 22.

In addition, the heat exchanger 22, considering that the lubricating oil used in the propulsion engine (E) is mixed into the liquefied gas returned by the fuel recovery unit 30, the lubricating oil from the liquefied gas flowing into the high pressure pump (21) The temperature of the liquefied gas can be adjusted above the temperature that does not freeze.

That is, when the heat exchanger 22 is mixed with the liquefied gas delivered from the fuel storage unit 10 to the high pressure pump 21 and the liquefied gas delivered from the fuel recovery unit 30 to the high pressure pump 21, the liquefied gas The temperature of the liquefied gas is controlled to be below the boiling point and above the freezing point of the lubricant.

The heat exchanger 22 may implement heat exchange with liquefied gas using various heat exchange media supplied through the medium supply line L21. For example, the heat exchange medium may be sea water, fresh water, glycol water, exhaust, etc. It is not limited.

The temperature of the liquefied gas heated by the heat exchanger 22 may be different from the required temperature of the propulsion engine E. When the pressure is applied by the high pressure pump 21 provided downstream of the heat exchanger 22, the temperature of the liquefied gas is Because it can increase somewhat. Therefore, the heat exchanger 22 controls the heating or cooling of the liquefied gas so that the temperature of the liquefied gas flowing into the propulsion engine E is appropriate in consideration of the temperature rise of the liquefied gas during the pressurization process of the high pressure pump 21. Can.

The high pressure pump 21 is provided downstream of the heat exchanger 22 in the fuel supply line L20 and pressurizes the liquefied gas whose temperature is controlled by the heat exchanger 22 to a pressure required by the propulsion engine E. . The pressure required by the propulsion engine (E) may be 20 to 50 bar, but may vary depending on the specifications of the propulsion engine (E).

The type of the high pressure pump 21 is not particularly limited, and the high pressure pump 21 may be provided in parallel so that a plurality of high pressure pumps 21 can be backed up to each other as shown in the drawings.

However, the high pressure pump 21, in order to suppress the generation of cavitation (cavitation) in the pressurization process, liquefied gas may be introduced into the liquid. To this end, the heat exchanger 22 can control the temperature of the liquefied gas as described above.

The pressure of the liquefied gas sucked into the high pressure pump 21 may correspond to the pressure of the liquefied gas discharged by the transfer pump 111. In addition, it can also correspond to the pressure of the liquefied gas decompressed by the pressure reducing valve 31 of the fuel recovery unit 30 to be described later.

When the suction pressure of the high pressure pump 21 is increased (eg, about 20 bar or more, which is a critical pressure of liquefied gas), the load of the high pressure pump 21 is reduced, while the load of the transfer pump 111 is increased. However, as the degree of decompression by the pressure reducing valve 31 in the fuel recovery unit 30 decreases (a state in which the boiling point is relatively high), the recovered liquefied gas can be prevented from being vaporized.

On the other hand, when the suction pressure of the high pressure pump 21 is lowered (for example, about 5 to 10 bar below the critical pressure of liquefied gas), the load of the high pressure pump 21 is increased while the load of the transfer pump 111 is reduced. In this case, in order to match the suction pressure of the high pressure pump 21, the degree of decompression by the pressure reducing valve 31 is increased (the boiling point is low), and the recovered liquid liquefied gas may be vaporized and flow into the high pressure pump 21. There is.

Nevertheless, this embodiment can lower the suction pressure of the high pressure pump (21). For example, the suction pressure of the high pressure pump 21 (the discharge pressure of the transfer pump 111) may be 1 to 10 bar. Through this embodiment, for the configurations of the devices and lines from the fuel storage unit 10 to the front end of the high-pressure pump 21, it is possible to lower the operating pressure, resulting in an innovative reduction of installation costs as well as maintenance costs. It is possible.

However, as mentioned above, the problem of vaporization of the liquefied gas to be introduced into the high pressure pump 21 remains. In this embodiment, the cooler 32 may be added to the fuel recovery unit 30 to solve this problem. This will be described later.

The filter 23 is provided downstream of the high pressure pump 21 in the fuel supply line L20 and filters 23 the liquefied gas pressurized by the high pressure pump 21 to be transmitted to the propulsion engine E. The material that the filter 23 rings on the filter 23 may mean various foreign materials that degrade the efficiency of the propulsion engine E, and the type is not limited.

The fuel supply unit 20 may provide a fuel supply valve (not shown) between the filter 23 and the propulsion engine E. At this time, the fuel supply valve and the pressure reducing valve 31 of the fuel recovery unit 30 to be described later ), it can be referred to as consisting of a single train can be referred to as FVT (fuel valve train).

The fuel recovery unit 30 recovers the excess liquid liquefied gas mixed with the lubricating oil discharged from the propulsion engine E. Unlike commercial engines (ME-GI, XDF, etc.) that receive and consume LNG in the gas phase, the propulsion engine (E) (ME-LGI, etc.) in the present invention receives LPG, etc. in liquid form and consumes excess liquid fuel. It has a structure to discharge.

This is because, unlike the gaseous phase, the fine control of the fuel supply amount is not easy in the case of the liquid phase, and thus excess fuel is generated as the propulsion engine E is supplied with a sufficient amount of the liquid fuel.

However, the liquefied gas recovered from the propulsion engine (E) is not liquefied gas before entering the propulsion engine (E), but liquefied gas that has passed through the interior of the propulsion engine (E), which corresponds to the required pressure of the propulsion engine (E). While having a temperature/pressure condition (eg, around 45 bar, 50 degrees C or more), lubricating oil used in the propulsion engine E may be mixed inside the liquefied gas.

Therefore, since the surplus liquefied gas recovered by the fuel recovery unit 30 is mixed with lubricating oil, it is preferable that the fuel recovery unit 30 does not deliver the liquefied gas to the cargo tank 11 to prevent cargo contamination. . That is, the fuel recovery unit 30 may transfer the liquid liquefied gas to the high-pressure pump 21 instead of the cargo tank 11 so as to be re-introduced into the propulsion engine E.

The fuel recovery unit 30 includes a fuel recovery line L30 extending from the propulsion engine E, and includes a pressure reducing valve 31 and a cooler 32 provided in the fuel recovery line L30.

The pressure reducing valve 31 decompresses the liquid liquefied gas. The pressure reducing valve 31 may be a Joule-Thomson valve, and may be provided to constitute a fuel supply train (FVT) together with the fuel supply valve of the fuel supply unit 20 as described above.

The pressure reducing valve 31 can reduce the liquefied gas of high pressure (about 30 to 50 bar or so) recovered from the propulsion engine E to match the suction pressure of the high pressure pump 21. At this time, when the pressure reducing valve 31 decompresses the liquefied gas to a critical pressure (for example, 20 bar or more), it is mixed with the liquefied gas supplied from the fuel storage unit 10 and then gas phase liquefaction in the process of flowing into the high pressure pump 21 Gas may not be produced. However, in this case, the suction pressure of the high-pressure pump 21 is higher than the intergranular pressure, and the components upstream of the transfer pump 111 and the high-pressure pump 21 must be set to an expensive specification suitable for a critical pressure or higher.

However, in the present embodiment, the pressure reducing valve 31 can reduce the liquefied gas above the critical pressure to a pressure below the critical pressure (for example, 1 to 10 bar), thereby lowering the suction pressure of the high pressure pump 21, thereby transferring the pump The discharge pressure of (111) is set to be below the critical pressure in response to the pressure drop of the pressure reducing valve (31), so that the transfer pump (111) and the fuel supply line (L20) upstream of the high pressure pump (21) are relatively low pressure It can be installed with low-cost specifications tailored to.

However, in this case, the boiling point of the liquefied gas is lowered due to the pressure drop. The liquefied gas recovered from the propulsion engine (E) is heated to the required temperature of the propulsion engine (E) and further heated while passing through the propulsion engine (E). Since it can be in a state (around 60 degrees C), the liquefied gas can be vaporized when decompressed.

Of course, the recovered liquefied gas may be partially liquefied again while being mixed with the liquefied gas supplied through the fuel supply unit 20, but it is clear that a cavitation problem may occur when the gaseous liquefied gas flows into the high pressure pump 21. Therefore, a cooler 32 is provided downstream of the pressure reducing valve 31 in the fuel recovery line L30 to prevent vaporization of liquefied gas.

The cooler 32 cools the decompressed liquefied gas to flow into the high pressure pump 21 as a liquid. The cooler 32 may utilize various refrigerants that are not limited, and may cool the liquefied gas below the boiling point of the decompressed liquefied gas.

Cooling by the cooler 32 may be achieved in consideration of mixing with liquefied gas delivered from the fuel storage unit 10 to the high pressure pump 21, so the cooler 32 is somewhat higher than the boiling point of the decompressed liquefied gas. Control of cooling the liquefied gas to a temperature is also possible.

The liquid phase (or the state close to the liquid phase) liquefied gas cooled by the cooler 32 is mixed upstream of the high pressure pump 21 in the fuel supply line L20 through the fuel recovery line L30, and the fuel recovery line ( A mixer (not shown) may be provided at a point where L30) is connected to the fuel supply line L20.

As described above, this embodiment allows the liquefied gas to be recovered to be decompressed below the critical pressure by the pressure reducing valve 31, thereby lowering the specifications of the components provided upstream of the high pressure pump 21, as well as the installation cost, operation, maintenance, and maintenance. The effect of reducing all costs can be achieved.

In addition, the fuel recovery unit 30, the fuel recovery line (L30) may be provided to have a partially parallel structure, a collection tank 34 (collecting tank) is provided on one side in the parallel fuel recovery line (L30) , Vent mast 36 is connected to the collection tank 34.

The fuel recovery line (L30) is branched downstream from the pressure reducing valve (31) and is partially composed in parallel and then joined again to be connected to the fuel supply line (L20), and the collection tank (34) is downstream of the pressure reducing valve (31). Is placed.

The collection tank 34 may store a portion of the liquefied gas recovered through the fuel recovery unit 30, wherein the liquefied gas delivered to the collection tank 34 is the flow rate of the liquefied gas supplied from the fuel storage unit 10 And the required flow rate of the propulsion engine (E), the state of the liquefied gas recovered, and the like can be determined in general. For example, if the flow rate of the liquefied gas recovered is large, at least a portion of the liquefied gas may be temporarily stored in the collection tank 34.

Alternatively, the collection tank 34 may be provided for purging. When purging, the purging gas is injected from the outside to the fuel supply unit 20 and the like, and the purging gas passing through the propulsion engine E is recovered through the fuel recovery line L30 and transferred to the collection tank 34. At this time, the purging gas may be discharged to the outside using a vent mast 36 connected to the collection tank 34.

The vent mast 36 is connected from the collection tank 34 through a vent line L32, and can vent liquefied gas or the like to an outside in an abnormal driving situation in which a vent is required, such as an operation stop of the propulsion engine E. . Of course, for this purpose, the collection tank 34 may receive liquefied gas in abnormal operation and discharge it to the vent mast 36.

Alternatively, the vent mast 36 may be used as a configuration to implement purging by discharging the purging gas circulated to the collection tank 34 to the outside when purging the fuel supply unit 20 or the like.

The reliquefaction unit 40 liquefies the boil-off gas generated in the fuel storage unit 10 and returns it to the fuel storage unit 10. The reliquefaction unit 40 may include a liquefier 41 that cools the evaporation gas to a boiling point or lower using various refrigerants.

The liquefier 41 is liquefied by cooling the evaporation gas using nitrogen, a mixed refrigerant (MR), or the like. In this case, the re-liquefaction line L40 may be connected to the liquefier 41 from the cargo tank 11 that is the fuel storage unit 10.

In the re-liquefaction line (L40) connected from the cargo tank (11) to the liquefier (41), gaseous vaporized gas discharged through the vapor phase main line (VM) of the cargo tank (11) can flow, and the liquefier (41) In the re-liquefaction line (L40) connected to the cargo tank 11, the liquefied liquid vaporized gas cooled by the liquefier 41 may flow.

However, in order to increase the liquefaction efficiency, a compressor (not shown) that increases the boiling point of the evaporated gas may be disposed on the reliquefaction line L40 between the cargo tank 11 and the liquefier 41. However, even when the compressor 124 is provided, a pressure reducer may be omitted in the reliquefaction line L40 between the liquefier 41 and the cargo tank 11, which is the cargo tank 11 through the reliquefaction line L40. This is because decompression can be naturally performed as the evaporation gas is returned to the cargo tank 11, which is a bulky space.

The reliquefaction line (L40) connected from the liquefier (41) to the cargo tank (11) can transmit liquid vaporized gas into the cargo tank (11) through the liquid main line (LM) provided in the cargo tank (11). The liquid vaporized gas may be delivered to the lower side to be injected into the liquefied gas in the cargo tank 11 or sprayed on the vaporized gas generated in the cargo tank 11 to be sprayed from the upper side to reduce the emission amount of the vaporized gas. Of course, the manner in which the liquid vaporized gas is returned in the cargo tank 11 is not limited to the above.

As described above, in the present embodiment, when the fuel supply unit 20 supplies the liquefied gas stored in the fuel storage unit 10 to the propulsion engine E as a liquid, when the liquid liquefied gas is recovered from the propulsion engine E, the liquefied gas By reducing the pressure to below the critical pressure, the specification of the upstream portion of the high pressure pump 21 can be significantly reduced, while stable operation is possible by preventing liquefied gas from entering the high pressure pump 21 in the gas phase.

Hereinafter, the present embodiment will be mainly described in terms of differences from the previous embodiment, and parts omitted from description will be replaced with the previous content. This also applies to the contents of the third embodiment described later.

Referring to FIG. 2, in the gas processing system 1 according to the second embodiment of the present invention, the fuel recovery unit 30 may include a gas-liquid separation unit 35.

The gas-liquid separator 35 is provided downstream of the pressure-reducing valve 31 in the fuel recovery line L30 to separate the decompressed liquefied gas into gas-liquid so that only the liquid is introduced into the high-pressure pump 21. To this end, the gas-liquid separator 35 may be provided in a partially expanded form of a part of the fuel recovery line L30 in which liquefied gas is recovered, or in a container form for separating gas and liquid using a density difference. .

As described above, when the pressure reducing valve 31 of the fuel recovery unit 30 decompresses the liquefied gas to a critical pressure or less, the liquefied gas is in a state that can be vaporized according to the temperature. However, because the temperature of the liquefied gas recovered through the propulsion engine (E) is high, the liquefied gas may be vaporized even if the temperature is partially reduced during decompression, which causes cavitation in the high pressure pump (21) through which the liquefied gas flows. It becomes a problem.

Of course, to solve this, it is also possible to add a cooler 32 for cooling the liquefied gas downstream of the pressure reducing valve 31, but this embodiment replaces the gas-liquid separator 35 in the cooler 32 for more stable operation. Or can be used with the cooler 32. When both the cooler 32 and the gas-liquid separator are provided, the cooler 32 may cool the decompressed liquefied gas and transfer it to the gas-liquid separator 35.

The gas-liquid separator 35 may separate nitrogen components contained in the liquefied gas to be recovered. Since the nitrogen component is easily vaporized as a substance having a boiling point significantly lower than that of liquefied gas, the gas-liquid separator 35 may separate nitrogen and the like and discharge it to the outside. At this time, the outside may be a source of nitrogen or waiting.

When gas is accumulated in the gas-liquid separator 35, the pressure in the gas-liquid separator 35 rises. In this case, as the boiling point of the liquefied gas rises, the gas may naturally condense in the liquid, so the gas-liquid separator 35 can effectively prevent the gas from entering the high-pressure pump 21.

However, in the case of the nitrogen component, despite the increase in the internal pressure of the gas-liquid separation unit 35, it will not be condensed by the liquid in the gas-liquid separation unit 35. Can be discharged. The discharge of the nitrogen component can be controlled by adjusting the opening degree of the valve according to the internal pressure of the gas-liquid separator 35, the storage level, and the like.

Thus, in this embodiment, by placing the gas-liquid separator 35 provided in the form of an extended pipe on the fuel recovery line L30, only the liquid is returned to the high-pressure pump 21, thereby improving the cavitation of the high-pressure pump 21. Can be suppressed. Of course, even when the pressure reducing valve 31 decompresses the liquefied gas to a critical pressure or higher, the gas-liquid separation unit 35 may be used to separate nitrogen components.

For reference, the degree to which the pressure-reducing valve 31 decompresses the liquefied gas may be greater than or equal to a critical pressure or lower than a critical pressure in the present invention. However, when decompressing the pressure lower than the critical pressure, various means for preventing vaporization may be used. .

Referring to FIG. 3, in the gas treatment system 1 according to the third embodiment of the present invention, the heat exchanger 22 of the fuel supply unit 20 may be configured differently from the previous embodiment.

The heat exchanger 22 is the same as in the previous embodiment in that it changes the temperature of the liquefied gas supplied from the fuel storage unit 10 to the propulsion engine E. However, the heat exchanger 22 of the present embodiment may utilize liquefied gas recovered through the fuel recovery unit 30 for heat exchange.

That is, the heat exchanger 22 may exchange heat between the liquefied gas supplied from the fuel storage unit 10 to the propulsion engine E and the liquefied gas recovered from the fuel recovery unit 30. In this case, the heat exchanger 22 cools the liquefied gas of the fuel recovery unit 30 with the liquefied gas supplied to the propulsion engine E, so as to flow into the high pressure pump 21 as a liquid.

In the present invention, it is important not to generate gas when the liquefied gas recovered through the fuel recovery unit 30 flows into the high pressure pump 21. In the previous embodiment, the cooler 32, the gas-liquid separation unit 35, etc. Whereas, this embodiment may use (additionally) the heat exchanger 22.

Therefore, the heat exchanger 22 cools the liquefied gas decompressed by the pressure reducing valve 31 of the fuel recovery unit 30 to flow into the high pressure pump 21 as a liquid, thereby causing cavitation in the high pressure pump 21. It is possible to prevent.

In addition, the heat exchanger 22 may further utilize heat exchange media by further heat-exchanging the recovered liquefied gas with the liquefied gas delivered from the fuel storage unit 10. In this case, the heat exchanger 22 includes a stream (connected to the fuel supply line L20) through which liquefied gas supplied from the fuel storage unit 10 to the propulsion engine E flows, and liquefaction recovered from the fuel recovery unit 30 It may be at least three-stream structure having a stream through which the gas flows (connected to the fuel recovery line L30) and a stream through which the heat exchange medium flows.

At this time, the heat exchanger 22 may be of a fin-tube type or a PCHE type, and is preferably provided of a PCHE type to increase space utilization. This applies to all configurations that implement heat exchange within this specification.

A mixer 33 may be provided downstream of the heat exchanger 22 based on the fuel recovery line L30. The mixer 33 is provided between the heat exchanger 22 and the high-pressure pump 21 based on the fuel supply line L20, and is supplied from the liquefied gas passing through the heat exchanger 22 and the fuel storage unit 10 The liquefied gas is mixed and transferred to the high pressure pump 21.

When only the mixer 33 is used, the high temperature liquefied gas recovered from the propulsion engine E may be cooled while directly meeting the low temperature liquefied gas delivered from the fuel storage unit 10, but in this case, it is recovered due to rapid cooling. There is a risk that the lubricating oil contained in the liquefied gas freezes.

Therefore, in the present embodiment, the temperature drop is implemented stepwise so that the recovered liquefied gas is cooled by the low temperature liquefied gas and then mixed with the low temperature liquefied gas, thereby preventing freezing due to rapid cooling of the lubricant.

As described above, the present embodiment allows the liquefied gas recovered from the propulsion engine E to be cooled while being heat exchanged and mixed by the liquefied gas delivered from the fuel storage unit 10, and then recovered from the propulsion engine E to obtain a high pressure pump. The high pressure pump 21 can be protected by making the liquefied gas re-introduced to (21) into a liquid phase.

Referring to FIG. 4, in the gas treatment system 1 according to the fourth embodiment of the present invention, the heat exchanger 22 of the fuel supply unit 20 is disposed differently from the previous third embodiment.

In the case of the previous embodiment, the temperature control of the liquefied gas is made upstream of the high pressure pump 21, whereas in the case of the present embodiment, the temperature control of the liquefied gas is made downstream of the high pressure pump 21 similar to the LNG fuel supply system well known in the art. Can.

The heat exchanger 22 of the present embodiment may be provided downstream of the high pressure pump 21 in the fuel supply line L20, as opposed to the third embodiment. In this case, the heat exchanger 22 may heat-exchange the high-pressure liquefied gas pressurized by the high-pressure pump 21 and the liquefied gas recovered by the fuel recovery unit 30.

Specifically, the heat exchanger 22 heats the high-pressure liquefied gas pressurized by the high-pressure pump 21 to a critical pressure or higher with the liquefied gas of the fuel recovery unit 30. Therefore, the present embodiment can reduce the load to heat the liquefied gas supplied to the propulsion engine E, similar to the previous embodiment.

In addition, the heat exchanger 22 is similar to the previous embodiment, the stream flowing liquefied gas supplied from the fuel storage unit 10 to the propulsion engine E, and the stream flowing liquefied gas recovered from the fuel recovery unit 30 And, of course, it can be provided in a structure of three or more streams having a stream through which the heat exchange medium flows.

Since the heat exchanger 22 of this embodiment cools the liquefied gas recovered from the propulsion engine E and depressurized by the pressure reducing valve 31 with high pressure liquefied gas pressurized by the high pressure pump 21, compared to the previous embodiment Since the degree of cooling may be low, freezing of the lubricant can be sufficiently suppressed.

At this time, the liquefied gas recovered from the propulsion engine (E) and cooled in the heat exchanger (22) is from the fuel storage unit (10) through the mixer (33) provided upstream of the high pressure pump (21) in the fuel recovery line (L30). It can be mixed with the liquefied gas to be transferred, and can be in a state (liquid phase) that does not have any problem in the flow into the high pressure pump 21 while being mixed.

That is, the mixer 33 is provided upstream of the high pressure pump 21 and mixes the liquefied gas passing through the heat exchanger 22 and the liquefied gas supplied from the fuel storage unit 10 (mostly) a high pressure pump in a liquid state (21).

As described above, in the present embodiment, in order to prevent freezing of the lubricating oil to be recovered, the liquefied gas recovered using the liquefied gas downstream of the high-pressure pump 21 may be cooled, and the liquefied gas flowing into the high-pressure pump 21 may be cooled. Vapor production can be suppressed.

Referring to FIG. 5, in the gas processing system 1 according to the fifth embodiment of the present invention, the arrangement of the collection tank 34 provided in the fuel recovery unit 30 may be different from the previous embodiments.

The collection tank 34 receives the recovered liquefied gas and temporarily stores it. While the collection tank 34 is provided in the fuel recovery line L30, in the case of the previous embodiment, the portion where the collection tank 34 is provided in the fuel recovery line L30 is provided at least partially in parallel, whereas in the present embodiment A collection tank 34 may be provided at a point where the fuel recovery line L30 is connected to the fuel supply line L20.

That is, the collection tank 34 is provided at the confluence point of the fuel recovery line L30 and the fuel supply line L20 to implement the function of the mixer 33. Also, the collection tank 34 is provided upstream of the high pressure pump 21 based on the fuel supply line L20, and only the liquid from the liquefied gas flowing into the collection tank 34 can be delivered to the high pressure pump 21. . That is, the collecting tank 34 can also implement the function of the gas-liquid separator 35.

In addition, the collection tank 34 may include a heater 341 for heating the liquefied gas stored therein. That is, the collection tank 34 may be provided to implement the function of the heat exchanger 22 in addition to the functions of the mixer 33 or the gas-liquid separator 35 described above.

At this time, the heater 341 may be an in-tank heater provided in the form of a coil inside the collection tank 34, and may use electricity or heat exchange media introduced through a separate medium supply line L31.

Therefore, the collection tank 34 may heat the temporarily stored liquefied gas and transfer it to the high pressure pump 21. However, as repeatedly mentioned, when the gas phase flows into the high pressure pump 21, cavitation may be a problem, and the temperature of the liquefied gas heated by the collection tank 34 may be a temperature below the boiling point.

In this case, the fuel supply unit 20 is provided downstream of the high pressure pump 21 and may further include a heat exchanger 22 to change the temperature of the liquefied gas, and the heat exchanger 22 utilizes a heat exchange medium, Otherwise, the liquefied gas recovered from the fuel recovery unit 30 may be used. In the latter case, the heat exchanger 22 may be provided with a structure of at least two streams for exchanging the liquefied gas supplied from the fuel storage unit 10 to the propulsion engine E and the liquefied gas recovered from the fuel recovery unit 30. Can.

In the above case, the pressure of the liquefied gas delivered to the high pressure pump 21 may be less than or equal to the critical pressure. The pressure reducing valve 31 can reduce the liquefied gas to below the critical pressure, and the flow pressure upstream of the high pressure pump 21 is Since it may be below the critical pressure, the specifications for the components upstream of the high pressure pump 21 can be lowered. At this time, gas inflow into the high pressure pump 21 is prevented by the collecting tank 34.

Alternatively, the pressure of the liquefied gas delivered from the collection tank 34 to the high pressure pump 21 may be greater than or equal to a critical pressure at which no vaporization occurs at room temperature. In this case, since the pressure in the upstream of the high pressure pump 21 is greater than or equal to the critical pressure, specifications of the components upstream of the high pressure pump 21 may be increased, but on the other hand, a configuration such as a cooler 32 may be omitted.

A vent mast 36 is connected to the collection tank 34 through a vent line L32. The vent mast 36 vents at least a portion of the liquefied gas recovered to the collection tank 34 to the outside, wherein the vent may be made when the system is in an abnormal state or purging.

The vent line L32 may be connected to the vent mast 36 from the capture tank 34, and the vent line L32 vents the purging gas recovered into the collection tank 34 after purging of the fuel supply unit 20 and the like. (36). That is, when purging, the purging gas is collected in the collection tank 34 along the fuel recovery line L30 through the fuel supply unit 20 and the propulsion engine E, and then to the vent mast 36 along the vent line L32. It can be processed by being delivered.

As described above, in the present embodiment, the configuration of adjusting the temperature of the liquefied gas in the upstream of the high pressure pump 21 and the configuration of mixing the recovered liquefied gas with the liquefied gas supplied from the fuel storage unit 10 are collected in one collection tank 34 ) To simplify the system and significantly reduce installation/maintenance/repair costs.

Referring to FIG. 6, the gas processing system 1 according to the sixth embodiment of the present invention includes a heat exchanger 22, a high pressure pump 21, and a heater on the fuel supply line L20 of the fuel supply unit 20 (24) is provided in turn. Hereinafter, this embodiment will be described in comparison with the third embodiment shown in FIG. 3.

Compared to the third embodiment, in the present embodiment, the fuel supply unit 20 may further include a heater 24 downstream of the high pressure pump 21. That is, the fuel supply unit 20 includes a high pressure pump 21, a heat exchanger 22 provided upstream of the high pressure pump 21 to change the temperature of the liquefied gas, and a heater 24 provided downstream of the high pressure pump 21 It may include.

At this time, the heat exchanger 22 is configured to cool the liquefied gas decompressed by the pressure reducing valve 31 of the fuel recovery unit 30 to flow into the high pressure pump 21 as a liquid, from the fuel storage unit 10 The liquefied gas supplied to the propulsion engine E and the liquefied gas recovered from the fuel recovery unit 30 may be exchanged.

Specifically, the heat exchanger 22 has at least two streams having a stream through which the liquefied gas supplied from the fuel storage unit 10 to the propulsion engine E flows, and a stream through which the liquefied gas recovered from the fuel recovery unit 30 flows. It can be provided with the above structure.

The heater 24 heats the liquefied gas downstream of the high pressure pump 21 and changes it according to the required temperature of the propulsion engine E. That is, in the present embodiment, the temperature control of the liquefied gas is made upstream of the high pressure pump 21, and also the temperature control of the liquefied gas can be made downstream of the high pressure pump 21. Liquefaction according to the required temperature of the propulsion engine E Gas temperature control can be achieved primarily in the heater 24 downstream of the high pressure pump 21.

The liquefied gas recovered by the fuel recovery unit 30 is transferred to the heat exchanger 22 and cooled in the heat exchanger 22, and then the heat exchanger 22 and the high pressure pump 21 in the fuel supply line L20 Through the mixer 33 provided therebetween, it may be mixed with liquefied gas supplied from the fuel storage unit 10.

In addition, the fuel recovery unit 30 further includes a bypass line L34 in addition to the fuel recovery line L30 connected to the mixer 33 via the heat exchanger 22 via the pressure reducing valve 31. can do. The bypass line (L34) allows the recovered liquefied gas to be transferred to the liquefied gas supplied to the propulsion engine (E) by bypassing the heat exchanger (22).

The bypass line L34 may be connected to the fuel supply line L20 between the mixer 33 and the high pressure pump 21, or may be directly connected to the mixer 33. A bypass valve (not shown) is provided in the bypass line L34, and the bypass can be controlled according to the operation state of the propulsion engine E.

Specifically, the fuel recovery unit 30 transfers liquefied gas to the heat exchanger 22 along the fuel recovery line L30 during normal operation of the propulsion engine E, and liquefied gas during initial operation of the propulsion engine E Bypass the heat exchanger 22 along the bypass line (L34) can be transferred to the high pressure pump (21).

This is because, during initial start-up, the liquefied gas recovered through the fuel recovery unit 30 differs in flow rate and temperature compared to liquefied gas during normal operation (for example, the flow rate is high or the temperature is high). Even without passing through the heat exchanger 22, there may be no risk of freezing of the lubricant.

Therefore, in the present embodiment, the temperature of the liquefied gas can be efficiently controlled by allowing the liquefied gas recovered in consideration of the operation state of the propulsion engine E to exchange heat with the liquefied gas supplied from the fuel storage unit 10 or bypass heat exchange. Do.

As described above, in the present embodiment, by placing the bypass line L34 in the fuel recovery line L30, considering the state of liquefied gas discharged from the propulsion engine E during the initial operation of the propulsion engine E, liquefaction is recovered. By bypassing the heat exchanger 22 and allowing the gas to re-enter the propulsion engine E, operational efficiency can be significantly improved.

Referring to FIG. 7, in the gas treatment system 1 according to the seventh embodiment of the present invention, the temperature change of the liquefied gas in both upstream and downstream of the high pressure pump 21 is similar to that in the previous sixth embodiment. It is possible. However, in the case of the previous embodiment, heat exchange between liquefied gas is utilized at least one side of the high pressure pump 21 upstream or downstream, whereas this embodiment may use heat exchange by the heat exchange medium both upstream and downstream of the high pressure pump 21.

Specifically, the fuel supply unit 20 includes a high pressure pump 21, a heat exchanger 22 provided upstream of the high pressure pump 21 to change the temperature of the liquefied gas, and a heater provided downstream of the high pressure pump 21 (24).

In this case, the pressure-reducing valve 31 of the fuel recovery unit 30 may reduce the recovered liquefied gas to a critical pressure or lower and deliver it to the high-pressure pump 21. However, in order to prevent the gas phase from flowing into the high pressure pump 21, a cooler 32 may be provided downstream of the pressure reducing valve 31 to cool the decompressed liquefied gas and flow into the high pressure pump 21 as a liquid. have.

When the pressure reduction by the pressure reducing valve 31 is lower than the critical pressure of the liquefied gas (for example, 6 to 10 bar), the transfer pump 111 of the fuel storage unit 10, etc., is a high pressure pump of the fuel supply unit 20 ( It is possible to transfer the liquefied gas to 21) below a critical pressure (eg, 6 to 10 bar).

Therefore, in the present embodiment, since the flow pressure in the transfer pump 111, the main line (VM, LM), etc. can be set below the critical pressure, this embodiment can significantly reduce the cost by lowering the design pressure of related components. .

However, in order to prevent gas from flowing into the high pressure pump 21, when the heat exchanger 22 heats the liquefied gas using a heat exchange medium, the temperature of the liquefied gas is at the pressure of the liquefied gas delivered from the fuel storage unit 10. It can be controlled below the boiling point.

In addition, considering that the lubricating oil is mixed with the recovered liquefied gas, the heat exchanger 22 sets the temperature of the liquefied gas to a temperature above the freezing point (about -18 degrees C) of the lubricating oil mixed with the liquefied gas of the fuel recovery unit 30. Can be controlled. That is, the heat exchanger 22 controls the temperature of the liquefied gas to the temperature between the boiling point and the freezing point of the lubricant.

However, since the temperature of the liquefied gas supplied from the fuel storage unit 10 to the high-pressure pump 21 may be increased while being mixed with the recovered liquefied gas, the heat exchanger 22 has a high-pressure pump by the fuel recovery unit 30. According to the temperature of the liquefied gas delivered to the (21), by controlling the temperature of the liquefied gas delivered from the fuel storage unit 10, it is possible to make the temperature of the liquefied gas flowing into the high pressure pump 21 below the boiling point. . That is, the liquefied gas delivered from the fuel storage unit 10 may be heated to a temperature lower than the boiling point in the heat exchanger 22 by a temperature interval (considering the heating component due to the mixing of the recovered liquefied gas).

The heater 24 provided downstream of the high pressure pump 21 may heat the liquefied gas to a required temperature of the propulsion engine E using a heat exchange medium. At this time, the heater 24 is provided in a structure that directly heats the liquefied gas using steam.

That is, in the present embodiment, the temperature control configuration of the liquefied gas provided in the fuel supply line L20 may use steam directly instead of using a heat exchange medium such as glycol water, thereby allowing the entire fuel supply unit 20 to be used. The flow rate of the cycle for supplying the glycol water can be reduced by about 60%, and all related configurations can be reduced.

As described above, in the present embodiment, the pressure of the liquefied gas recovered while controlling the temperature of the liquefied gas in both the upstream and downstream of the high pressure pump 21 can be reduced to reduce costs by reducing the specifications of the transfer pump 111 and the heater ( 24) By using the direct steam heating method, the supply structure of glycol water can be made compact.

Referring to FIG. 8, in the gas processing system 1 according to the eighth embodiment of the present invention, the fuel storage unit 10 may further include a fuel tank 12 as compared to the previous embodiments, and a configuration related thereto Can be added/modified.

The fuel storage unit 10 includes a plurality of cargo tanks 11 for storing liquefied gas as cargo, and a fuel tank 12 for storing the liquefied gas as fuel to be supplied to the propulsion engine E. At this time, the liquefied gas stored in the cargo tank 11 is not directly transmitted to the fuel supply unit 20, but instead can be delivered to the fuel tank 12 and then supplied to the propulsion engine E through the fuel tank 12.

In this case, a liquefied gas replenishing line L12 may be provided from the cargo tank 11 to the fuel tank 12, and a liquefied gas replenishing line L12 is provided with a pump (not shown) to supply the liquefied gas to the cargo tank ( 11) can be delivered to the fuel tank (12). Of course, the liquefied gas replenishment line (L12) is provided in the cargo tank 11, so the liquefied gas can be delivered to the fuel tank 12 through the cargo pump 111a used for unloading the liquefied gas. It may not be.

Cargo tank 11 has been described above that can be divided into a plurality of groups. At least two groups of cargo tanks 11 among some groups of cargo tanks 11 are liquefied as fuel for propulsion engine E. Gas (such as propylene) may be loaded.

Therefore, the fuel tank 12 receives the liquefied gas from the cargo tank 11 loaded with liquefied gas (propane, butane, etc.) suitable as fuel for the propulsion engine E of the cargo tank 11, and the fuel supply unit 20 Can be delivered to.

The fuel tank 12 is a standalone type (SPB type, MOSS type) or a membrane type cargo tank 11 that stores liquefied gas in bulk at atmospheric pressure, or a standalone type (Type C, pressure vessel type) that stores liquefied gas at high pressure. Can. At this time, the storage pressure of the fuel tank 12 may be about 5 bar or less, which is equal to or less than the critical pressure of the liquefied gas, and an insulating structure may be provided on at least one side of the inside or outside of the wall to prevent vaporization of the liquefied gas.

The fuel tank 12 may be mounted on the upper deck 101 in the ship 100, and is provided to be supported on the upper deck 101 through a saddle. The fuel tank 12 does not interfere with components (main line (VM, LM), manifold, etc.) for loading/unloading the liquefied gas of the cargo tank 11 from the upper deck 101, and the ship 100 It may be arranged in a position that does not cover the visibility (visibility) when sailing. For example, the fuel tank 12 may be provided on the starboard side or starboard side of the bow side in the upper deck 101.

The fuel tank 12, which is a stand-alone pressure container, can store liquefied gas below a critical pressure. In this case, the liquefied gas stored in the fuel tank 12 is supplied with a fuel by the transfer pump 121 provided in the fuel tank 12. It can be delivered to (20). The transfer pump 121 of the fuel tank 12 may have a configuration similar to the transfer pump 111 of the cargo tank 11 described in the previous embodiment.

However, in the case of the fuel tank 12, unlike the cargo tank 11, since the storage amount of liquefied gas is small, a sufficient amount of liquefied gas is guaranteed in the fuel tank 12 in order to match the flow rate required by the propulsion engine E. There is a need. To this end, loading of the liquefied gas may be controlled through the liquefied gas replenishing line L12 from the cargo tank 11 to the fuel tank 12 according to the level of the fuel tank 12.

In addition, when the internal pressure in the fuel tank 12 is low, the pumping load of the transfer pump 121 in the fuel tank 12 may increase. For example, when the outside air is in a cold (about -20 degrees C) winter state, the internal pressure of the liquefied gas stored in the fuel tank 12 may be lowered.

Therefore, in the present embodiment, in order to smoothly implement liquefied gas discharge from the fuel tank 12 to the fuel supply unit 20, the internal pressure rise unit 122 may be placed in the fuel tank 12. At this time, the internal pressure riser 122 may be a pressure build-up unit (PBU) that receives and heats the liquefied gas stored in the fuel tank 12 and injects it back into the fuel tank 12.

That is, the fuel tank 12 may ensure the suction flow rate of the high pressure pump 21 of the fuel supply unit 20 by using the internal pressure raising unit 122 for heating the stored liquefied gas. At this time, the internal pressure riser 122 may be operated according to the outside temperature of the fuel tank 12, the amount of liquefied gas stored in the fuel tank 12, and/or the internal pressure of the fuel tank 12.

Since the fuel supply unit 20 and the fuel recovery unit 30 are the same/similar to the above-described embodiments, detailed descriptions are omitted. However, the re-liquefaction unit 40 of the present embodiment may be provided to re-liquefy all the vaporized gas of the cargo tank 11 and the fuel tank 12.

However, the cargo tank 11 may be loaded with unsuitable propylene or the like as fuel for the propulsion engine E, and liquefaction is also required for the propylene. However, when the cargo tank 11 and the fuel tank 12 share the liquefier 41 of the reliquefaction unit 40, the propylene of the cargo tank 11 is re-liquefied and then remains in the reliquefaction unit 40. The problem that the quality of the liquefied gas in the fuel tank 12 is changed by being recovered to the fuel tank 12 may occur.

Therefore, the present embodiment allows the liquefier 41 of the reliquefaction unit 40 to liquefy and return both the evaporation gas of the cargo tank 11 and the evaporation gas of the fuel tank 12, but is not suitable as fuel. Considering the case where the liquefied gas is loaded in the cargo tank 11, the boil-off gas of the fuel tank 12 flows into the liquefier 41 from the cargo tank 11 within a predetermined range from the liquefier 41. You can make it join the flow.

And/or, the boil-off gas of the fuel tank 12 liquefied in the liquefier 41 is branched from the flow from the liquefier 41 to the cargo tank 11 from the liquefier 41 within a predetermined range. It can be delivered to the fuel tank (12).

At this time, the preset range may be a position within 10% of the flow from the cargo tank 11 or the flow toward the cargo tank 11 based on the liquefier 41.

Specifically, the reliquefaction unit 40 is provided with a reliquefaction line (L40) for returning the evaporated gas discharged from the cargo tank 11 to the cargo tank 11 via the liquefier 41, and the fuel tank 12 ) To transfer the evaporated gas discharged from the liquefier 41 to the reliquefaction line (L40) upstream and branched from the reliquefaction line (L40) downstream of the liquefier (41) to refuel the fuel connected to the fuel tank (12) A line L41 may be included, and the point where the fuel reliquefaction line L41 joins the reliquefaction line L40 is close to the liquefier 41 side between the cargo tank 11 and the liquefier 41. It may be a position (a position close to within 10% of the liquefier 41), and the point at which the fuel reliquefaction line L41 branches off from the reliquefaction line L40 is also between the liquefier 41 and the cargo tank 11. It may be a position close to the liquefier 41 side (within 10% of the range of the liquefier 41).

Therefore, this embodiment, while allowing the boil-off gas of the cargo tank 11 and the fuel tank 12 to share the liquefier 41, the boil-off gas of the cargo tank 11 which is not suitable as fuel for the propulsion engine E When the re-liquefaction of the evaporation gas of the fuel tank 12 is prevented from being passed to the fuel tank 12, it is possible to ensure the operation efficiency of the propulsion engine E.

For reference, the boil-off gas of the fuel tank 12 flowing along the fuel reliquefaction line (L41) may be introduced into the liquefier 41, but partly branches to the boiler (B) to generate steam in the boiler (B). It can help.

In addition, the boil-off gas of the fuel tank 12 flows into the liquefier 41 independently of the flow flowing from the cargo tank 11 to the liquefier 41 or from the liquefier 41 to the cargo tank 11 It can be discharged from the liquefier 41 independently of the flow to be transmitted, so that liquefied gases of different compositions may not be mixed. That is, the re-liquefaction of the evaporation gas of the cargo tank 11 and the re-liquefaction of the evaporation gas of the fuel tank 12 may be processed at different times (at this time).

As described above, in the present embodiment, the fuel tank 12 is installed to allow the liquefied gas to be transmitted from the fuel tank 12 to the propulsion engine E, while smoothly discharging the liquefied gas from the fuel tank 12, When returning the liquefied gas of (12) to liquefaction, it is possible to prevent the fuel quality from being contaminated.

Referring to FIG. 9, the gas treatment system 1 according to the ninth embodiment of the present invention may include at least two fuel tanks 12, which will be described in detail below.

The fuel tank 12 is an independent pressure vessel and may have a high pressure fuel tank 12a that stores liquefied gas above a critical pressure, and a low pressure fuel tank 12b that is an independent pressure vessel and stores liquefied gas below a critical pressure. have.

At this time, the high pressure fuel tank 12a stores liquefied gas at a pressure of about 18 bar or more, so that the liquefied gas is not vaporized in a temperature range applied to the high pressure fuel tank 12a in the course of operating the system. Therefore, (almost) no boil-off gas is generated in the high-pressure fuel tank 12a, and the high-pressure fuel tank 12a may be referred to as a fully-pressurized type.

On the other hand, the low pressure fuel tank 12b stores liquefied gas at a pressure of about 5 bar. In this case, the low-pressure fuel tank 12b may generate evaporation gas therein according to conditions such as outside temperature, and may be referred to as a semi-pressurized type.

For the above configuration, the high pressure fuel tank 12a is provided as a specification capable of withstanding high pressure compared to the low pressure fuel tank 12b. To this end, the high-pressure fuel tank 12a may have a larger thickness of the insulation structure provided on the wall than the low-pressure fuel tank 12b.

In addition, the high pressure fuel tank 12a may be designed to have a size equal to or less than a predetermined size in order to be disposed in an empty space on the upper deck 101 of the ship 100 while confining liquefied gas at 18 bar or more. That is, the high-pressure fuel tank 12a may be provided with a capacity (eg, 1,300 m3) that cannot cover 10,000 NM, which is a voyage range generally considered when designing the ship 100.

In particular, the high-pressure fuel tank (12a) is further considering that the storage pressure is higher, the filling limit (for example, around 80%) lower than the 98% filling limit of the cargo tank 11 is set, for the vessel 100 to operate For storage of liquefied gas, the low pressure fuel tank 12b may be provided to have a larger volume than the high pressure fuel tank 12a.

That is, since the high-pressure fuel tank 12a alone cannot prepare for the operation of the ship 100, the low-pressure fuel tank 12b may be provided in a volume (for example, about 2,350 m3) that can cover 10,000 NM. In addition, since the storage pressure of the low-pressure fuel tank 12b is lower than that of the high-pressure fuel tank 12a, a filling limit may be further secured.

As described above, as the high-pressure fuel tank 12a stores the liquefied gas above the critical pressure, generation of evaporation gas is suppressed at room temperature, while the low-pressure fuel tank 12b stores the liquefied gas below the critical pressure. Since the evaporation gas is generated by the thermal penetration, the reliquefaction unit 40 of this embodiment is provided to re-liquefy the evaporation gas of the cargo tank 11 and the low pressure fuel tank 12b, and the high pressure fuel tank 12a ) May not be connected.

Thus, in this embodiment, the fuel tank 12 is divided into a high-pressure fuel tank 12a and a low-pressure fuel tank 12b, and the high-pressure fuel tank 12a stores liquefied gas at an unvaporized pressure, and the low-pressure fuel tank. As (12b), the liquefied gas may be stored at a predetermined pressure or higher, and fuel may be supplied using the transfer pump 121 in the high-pressure fuel tank 12a or the low-pressure fuel tank 12b.

At this time, since the pressure of the liquefied gas delivered to the high pressure pump 21 through the transfer pump 121 becomes greater than or equal to the storage pressure of the high pressure fuel tank 12a, the high pressure pump 21 by the fuel recovery unit 30 in connection with this ), the pressure of the liquefied gas recovered may also be greater than or equal to the critical pressure. Therefore, since the liquefied gas that is decompressed and recovered by the fuel recovery unit 30 is not vaporized, a configuration such as a cooler 32 may be omitted.

In addition, the present embodiment is provided with two fuel tanks 12 for storing liquefied gas at different pressures, so that the fuel tanks 12 can back up to each other, and also the fuel tank 12 (especially the high-pressure fuel tank ( 12a)) may be utilized as a container for storing liquefied gas during maintenance/repair of the cargo tank 11. This will be described in detail in other embodiments below.

Referring to FIG. 10, the gas processing system 1 according to the tenth embodiment of the present invention includes a high-pressure fuel tank 12a and a low-pressure fuel tank 12b while the fuel storage unit 10 has a low-pressure fuel tank. A fuel transmission unit 123 that directly connects the 12b and the high-pressure fuel tank 12a may be provided.

The fuel delivery unit 123 delivers liquefied gas through the liquefied gas delivery line L13 connected from the low pressure fuel tank 12b to the high pressure fuel tank 12a. As described above, since the high-pressure fuel tank 12a stores the liquefied gas at a critical pressure or higher, the generation of the evaporation gas at room temperature is suppressed, so the re-liquefaction section 40 has the evaporation gas and the low-pressure fuel tank of the cargo tank 11 ( It is provided to re-liquefy the boil-off gas of 12b).

However, when in operation, the boil-off gas generated in the low-pressure fuel tank 12b may be liquefied and returned to the liquefier 41.However, when moored, the re-liquefaction unit 40 generally does not produce electric power to operate ( It is necessary to cope with the occurrence of evaporation gas in the cargo tank 11 or the low-pressure fuel tank 12b, which generates only the minimum power for the hotel load in the ship 100 or receives the minimum power from the land).

Therefore, in the present embodiment, when the anchoring of the ship 100 for loading or unloading the cargo tank 11 by placing the fuel delivery unit 123, the liquefied gas of the low pressure fuel tank 12b is pressed into the high pressure fuel tank 12a. To the orphan fuel tank 12 to store the liquefied gas (or when the accumulator is provided on the propulsion engine E and can be detached with a propeller or clutch, or when the propulsion engine E is an electric propulsion method) It is also possible to supply to the propulsion engine E), and the operation of the reliquefaction unit 40 can be omitted or reduced during the anchoring period.

That is, when the fuel delivery unit 123 passes the liquefied gas of the high pressure fuel tank 12a to the low pressure fuel tank 12b, the high pressure fuel tank 12a stores the liquefied gas without vaporization, so the high pressure fuel tank 12a ) Can be omitted.

In addition, in the case of liquefied gas (heel) remaining in the cargo tank 11 before loading, it is transferred to the high-pressure fuel tank 12a through the liquefied gas replenishing line L12, so that the cargo tank 11 and low-pressure fuel during anchoring Since no evaporation gas is generated in both tanks 12b, the operation of the reliquefaction unit 40 can be omitted or reduced.

Furthermore, in the present embodiment, when changing the composition of the liquefied gas stored in the cargo tank 11, the fuel delivery unit 123 may be utilized. For example, the liquefied gas A is stored in the cargo tank 11 and the low-pressure fuel tank 12b. When the cargo of the cargo tank 11 is to be changed from A to B, the fuel delivery unit 123 has a low pressure. A of the fuel tank 12b is transferred to the high-pressure fuel tank 12a, and A remaining in the cargo tank 11 can also be captured by the high-pressure fuel tank 12a.

In this case, since the low-pressure fuel tank 12b is empty by the fuel transmission unit 123, when loading B thereafter, B can be loaded into both the cargo tank 11 and the low-pressure fuel tank 12b. . Of course, A and B may be fuels suitable for the propulsion engine E.

Therefore, in the present embodiment, in the process of loading (by changing the type of liquefied gas cargo) while anchored at a terminal, etc., the high-pressure fuel tank 12a is used to reduce/minimize evaporative gas treatment, thereby significantly reducing operating costs. can do.

Referring to FIG. 10, in the gas processing system 1 according to the tenth embodiment of the present invention, the fuel delivery unit 123 in the ninth embodiment transfers evaporated gas instead of (or in addition to liquefied gas) liquefied gas Implement

The fuel delivery unit 123 of the present embodiment may transfer the evaporation gas from the low pressure fuel tank 12b to the high pressure fuel tank 12a. At this time, considering that there is a pressure difference between the low-pressure fuel tank 12b and the high-pressure fuel tank 12a, the fuel delivery unit 123 uses the boil-off gas generated in the low-pressure fuel tank 12b to the internal pressure of the high-pressure fuel tank 12a. Compressed with a compressor 124 to correspond to the can be delivered to the high-pressure fuel tank (12a).

That is, the compressor 124 of the fuel delivery unit 123 compresses the boil-off gas by the difference in the internal pressure between the low-pressure fuel tank 12b and the high-pressure fuel tank 12a, but the boil-off gas in the low-pressure fuel tank 12b is greater than or equal to the critical pressure. Compressed to deliver to the high-pressure fuel tank (12a), the high-pressure fuel tank (12a) may supply the evaporated gas delivered by the fuel delivery unit 123 to the storage or propulsion engine (E).

In this way, when the boil-off gas of the low-pressure fuel tank 12b is delivered to the high-pressure fuel tank 12a, the need to re-liquefy the boil-off gas of the low-pressure fuel tank 12b and return it may be omitted/minimized. Therefore, the reliquefaction unit 40 can omit the operation of the reliquefaction unit 40 with respect to the fuel tank 12.

That is, in the present embodiment, by placing the fuel delivery unit 123 that delivers the evaporation gas of the low pressure fuel tank 12b to the high pressure fuel tank 12a, the reliquefaction unit 40 is not a fuel tank 12 but a cargo tank. The size of the reliquefaction unit 40 can be compacted and the refrigerant treatment cost required for liquefaction can be reduced by providing a specification that can only process the liquefied gas of (11).

Referring to FIG. 11, in the gas processing system 1 according to the eleventh embodiment of the present invention, the fuel recovery unit 30 recovers liquefied gas and transfers it to the high pressure pump 21, but the fuel recovery unit 30 The liquefied gas recovered by can be recovered in the fuel tank 12 of the fuel storage unit 10 instead of being recovered in the fuel supply unit 20.

That is, in the fuel tank 12 (eg, the high-pressure fuel tank 12a) of the fuel storage unit 10, the fuel recovery line L30 is directly connected, and the liquefied gas recovered by the fuel recovery line L30 is internal. Can be injected with In this case, the fuel recovery line L30 may spray liquefied gas on the upper part in the fuel tank 12, but the injection method is not limited thereto.

The fuel recovery unit 30 recovers the high-pressure/high-temperature liquefied gas discharged from the propulsion engine E by the pressure-reducing valve 31 and recovers it to the fuel tank 12, and recovers the recovered high-temperature liquefied gas at high pressure. Transfer to the fuel tank 12a may increase the internal pressure and temperature of the high-pressure fuel tank 12a. That is, the function of the internal pressure rise unit 122 described above with reference to FIG. 8 may be implemented using the recovered liquefied gas.

Therefore, in the present embodiment, when the amount of liquefied gas required by the propulsion engine E is, for example, 3 to 4 m3 per hour, the returned high-temperature liquefied gas is sprayed into the high-pressure fuel tank 12a in the fuel storage unit 10. By increasing the amount of liquefied gas delivered to the propulsion engine (E), it is possible to ensure stable operation of the propulsion engine (E).

The high-pressure fuel tank 12a through which the liquefied gas is recovered by the fuel recovery unit 30 may be connected to the vent mast 36 for venting of liquefied gas and purging gas during abnormal operation. That is, the vent line L32 is connected from the high pressure fuel tank 12a to the vent mast 36, and the liquefied gas of the high pressure fuel tank 12a or the purging gas recovered through the fuel recovery line L30 is vent line ( L32) to be transferred to the vent mast 36 to be discharged to the outside.

However, in the case of purging gas, since explosive substances remaining in the fuel supply unit 20 or the like during the purging process may be mixed, discharge through the vent mast 36 may cause environmental pollution.

Therefore, in the present embodiment, the purging gas discharged from the high pressure fuel tank 12a through the vent line L32 may be transmitted to the low pressure fuel tank 12b instead of being transferred to the vent mast 36. For this, the purge gas recovery line L33 connected to the low-pressure fuel tank 12b may be branched to the vent line L32.

Accordingly, the purging gas recovered after purging of the fuel supply unit 20 by the fuel recovery unit 30 flows into the high-pressure fuel tank 12a along the fuel recovery line L30, and then exits along the vent line L32. After coming out, it can be stored in the low pressure fuel tank 12b through the purge gas recovery line.

At this time, the purging gas recovered through the purging gas recovery line L33 may have a pressure equal to or higher than the internal pressure of the low-pressure fuel tank 12b. Therefore, when the purging gas flows in, the pressure of the low pressure fuel tank 12b increases.

In this case, in the present embodiment, the low-pressure fuel tank 12b may transfer the liquefied gas to the fuel supply unit 20 by internal pressure without the transfer pump 121. That is, the low-pressure fuel tank 12b is able to omit the transfer pump 121 or reduce the load on the transfer pump 121 by increasing the internal pressure by the inflow of purging gas.

Therefore, in an abnormal situation such as a stop in which the propulsion engine E is tripped according to a specific terminal condition, the present embodiment can regulate the internal pressure without discharging the purging gas to the outside (using the reliquefaction unit 40). It can be recovered and collected by the fuel tank 12b to control the purge gas discharge to the outside air, thereby improving safety and preventing air pollution.

In particular, the low-pressure fuel tank 12b is capable of adjusting the internal pressure through liquefaction return of evaporated gas, so that the internal pressure of the low-pressure fuel tank 12b is maintained so that the internal pressure of the low-pressure fuel tank 12b is increased by the high-pressure purging gas. , It is possible to reduce the load of liquefied gas discharge from the low pressure fuel tank (12b).

Of course, the purging gas can be delivered to the low pressure fuel tank 12b as above, but the liquefied gas recovered in addition to the purging gas is also transferred to the low pressure fuel tank 12b through the high pressure fuel tank 12a in the same manner as the flow of the purging gas. It is of course also possible to increase the internal pressure of the low-pressure fuel tank 12b.

As an example, the high-pressure fuel tank 12a stores liquefied gas at a pressure that does not vaporize at room temperature, but as the liquefied gas above room temperature flows into the high-pressure fuel tank 12a through the fuel recovery unit 30, the high-pressure fuel Evaporated gas is generated in the tank 12a and can be transferred to the low pressure fuel tank 12b through the vent line L32 and the purging gas recovery line L33.

Of course, as in the other embodiments described above, the present embodiment also suppresses the generation of evaporation gas at room temperature as the high-pressure fuel tank 12a stores liquefied gas above a critical pressure, and the low-pressure fuel tank 12b has independent pressure. As the container and the liquefied gas are stored below the critical pressure, the reliquefaction unit 40 re-liquefies the evaporation gas of the cargo tank 11 and the low pressure fuel tank 12b, but is not connected to the high pressure fuel tank 12a. It may not.

As described above, in the present embodiment, the recovered liquefied gas is directly introduced into the high-pressure fuel tank 12a to increase the internal pressure of the high-pressure fuel tank 12a to stably implement liquefied gas fuel supply, and the purging gas is a low-pressure fuel tank. By collecting it in (12b), concerns about environmental pollution can be eliminated.

12 is a partial side view of a ship to which a gas treatment system according to a twelfth embodiment of the present invention is applied, and FIG. 13 is a partial plan view of a ship to which a gas treatment system according to a twelfth embodiment of the present invention is applied.

12 and 13, in the gas processing system 1 according to the twelfth embodiment of the present invention, the fuel storage unit 10 may include a plurality of cargo tanks 11 and separate fuel tanks. Even if the (12) is not provided, a space for separately storing the liquefied gas supplied as fuel of the propulsion engine E may be provided.

Specifically, the fuel storage unit 10 may allow the cargo storage space 113 and the fuel storage space 114 to be provided in at least one of the plurality of cargo tanks 11 at a time.

At this time, the cargo tank 11 may be provided with a sealed partition wall 112 separating two or more spaces in various directions, such as a front-rear direction or a left-right direction, and the cargo storage space 113 by the partition wall 112. The fuel storage space 114 for storing the liquefied gas to be supplied to the propulsion engine E may be configured to be partitioned.

As described above, the cargo tank 11 may store liquefied gas at normal pressure, and may be a membrane type or a stand-alone tank (excluding Type C), so the fuel storage space 114 formed in the cargo tank 11 is also 98%. Filling limit is applied, so it is possible to store maximum liquefied gas in a specific volume.

At this time, the partition wall 112 is provided under the dome 115 in consideration of the position of the dome 115 provided in the cargo tank 11, so that the cargo storage space 113 and the fuel storage space 114 are one dome. It may be provided to share 115.

The liquefied gas in the cargo storage space 113 is loaded/unloaded through the cargo pump 111a and the main lines (VM, LM), and the liquefied gas in the fuel storage space 114 is a transfer pump 111 and a fuel supply line It is supplied to the propulsion engine (E) through (L20). At this time, since both the cargo storage space 113 and the fuel storage space 114 need a structure (line and dome 115) that communicates with the outside, this embodiment is a dome 115 that is basically provided in the cargo tank 11 The fuel storage space 114 can also be utilized to discharge liquefied gas.

The dome 115 of the cargo tank 11 may be provided with a bias toward the bow or stern side of the ship 100 accommodating the cargo tank 11, as shown in FIG. 13, considering the arrangement of the dome 115 112 may be provided biased to one side in the front-rear direction from the inside of the cargo tank (11).

Of course, the dome 115 may be disposed at the center in the left and right directions, so when the partition 112 divides the interior of the cargo tank 11 in the left and right directions, the partition wall 112 may be disposed at the center. In addition, one or more partition walls 112 may be provided to form one or more fuel storage spaces 114.

The cargo storage space 113 and the fuel storage space 114 divided by the partition wall 112 may be provided in the same volume or different volumes, or the volumes of the spaces divided by the partition wall 112 may be the same, A small number of spaces are fuel storage spaces 114, and the remaining large number of spaces can be used as cargo storage spaces 113.

For example, when the interior of the cargo tank 11 is divided into four spaces by two partition walls 112, only one space can be used as the fuel storage space 114, in this case, the space divided into four spaces. They can all be provided to share one dome 115.

To allow the dome 115 to be shared, the partition wall 112 may have a height communicating two spaces within the dome 115 as shown in FIG. 12, instead of completely isolating the space inside the cargo tank 11. That is, the spaces separated by the partition wall 112 may communicate with each other so that the evaporation gas moves through the dome 115.

When the evaporation gas generated in the cargo storage space 113 or the fuel storage space 114 flows toward the dome 115, the evaporation gas of the fuel storage space 114 is a cargo storage space because the evaporation gas is lighter than liquefied gas. There is little risk of being transferred to the liquefied gas of 113 or the boil-off gas of the cargo storage space 113 to be introduced into the liquefied gas of the fuel storage space 114.

However, when the boil-off gas in the cargo storage space 113 is mixed with the boil-off gas in the fuel storage space 114 and then re-liquefied and returned, there is a fear that the liquefied gas quality of the fuel storage space 114 may deteriorate. In particular, in the cargo storage space 113, liquefied gas (butane/propane or the like) which is suitable or inappropriate as fuel of the propulsion engine E is stored, whereas the fuel storage space 114 has a propulsion engine (E) unlike the cargo storage space 113. This is because the composition of liquefied gas stored in the two storage spaces may be different because only suitable liquefied gas is stored as fuel.

Accordingly, the partition wall 112 is separated from at least the cargo storage space 113 and the fuel storage space 114 so that the vaporized gas can be isolated, unlike in the drawing, the partition wall 112 may be provided with a structure that completely separates the two spaces. It might be.

The two spaces separated by the partition wall 112 may be independently made of liquefied gas pumping and re-liquefaction, but when loading suitable liquefied gas as fuel of the propulsion engine E into the cargo storage space 113, The liquefied gas in the cargo storage space 113 may be supplemented with the fuel storage space 114.

To this end, a partially penetrated opening is formed in the partition wall 112 and a liquefied gas delivery valve (not shown) may be provided, so that liquefied gas delivery through the partition wall 112 may be performed. Or after the liquefied gas loaded in the cargo storage space 113 is discharged from the cargo tank 11, the liquefied gas extending from the main line (VM, LM) or the fuel supply line (L20) toward the fuel storage space 114 Of course, liquefied gas may be delivered through the replenishment line L12.

As described above, this embodiment forms a separated space using a partition wall 112 inside any one of the cargo tanks 11, and allows the separated space to be used as the fuel storage space 114 (propylene Excluding liquefied gas), it is not necessary to place the fuel tank 12 on the upper deck 101, so that the visibility problem can be solved, and does not cause interference with other equipment in the upper deck 101.

Referring to FIG. 14, the gas treatment system 1 according to the thirteenth embodiment of the present invention is provided in that the bulkhead 112 is provided in the cargo tank 11 which is a membrane type or a standalone tank (except for Type C). Similar to the 12th embodiment, the partition wall 112 is provided in a closed type, and is characterized in that the space is completely separated by the partition wall 112.

That is, at least one of the plurality of cargo tanks 11 included in the fuel storage unit 10 is provided with a sealed partition wall 112 that completely divides the storage space into two or more. In this case, two or more storage spaces divided by the partition wall 112 do not communicate with each other in the cargo tank 11. Therefore, the cargo pump or the transfer pump 111 provided in the cargo tank 11 to discharge liquefied gas to the outside may be provided independently for each of a plurality of storage spaces divided by the partition wall 112.

The partition wall 112 may be in a form of completely dividing the storage space from side to side. That is, the partition wall 112 may be a vertical partition wall 112 provided in the front-rear direction of the ship 100.

In the case of a liquefied gas carrier having a cargo tank 11 for storing liquefied gas as cargo, cargo according to IGC code (International code for construction & equipment of ships carrying liquefied gases in bulk) A certain gap should be provided between the tank 11 and the side shell plate 102.

For example, in the case of an LPG carrier, a single-hull structure is provided on the outside of the cargo tank 11 to surround the outer shell 102 of the single wall, and the space between the outer shell 102 and the wall of the cargo tank 11 is the cargo tank. It depends on the volume of (11).

That is, the cargo tank 11 is arranged inside from the outer shell plate 102 in accordance with the space between the cargo tank 11 and the outer shell plate 102 according to the IGC code based on the volume of the storage space, and the distance is within the ship. It is not possible to secure the load of liquefied gas. At this time, the larger the volume of the cargo tank 11, the larger the gap.

In the present embodiment, the bulkhead 112 for completely dividing the storage space of the cargo tank 11 is placed so as to ensure the maximum storage capacity of the liquefied gas in the ship while satisfying the interval according to the IGC code. Based on the volume of the IGC code, the cargo tank 11 according to the IGC code and the side shell plate 102 may be spaced apart from the side shell plate 102 of the ship 100 by a distance D1 smaller than the gap D0. .

Since the interval according to the IGC code is determined according to the volume of the storage space to be isolated, this embodiment can reduce the reference volume when calculating the interval of the IGC code through the sealed partition wall 112, so that the interval Can be reduced from D0 to D1. That is, in the present embodiment, the space between the cargo tank 11 and the side shell plate 102 is reduced by placing the partition wall 112 in the form of dividing the storage space left and right within the cargo tank 11, thereby reducing the cargo tank 11 itself. Can grow.

However, when two or more partition walls 112 are provided, there is a problem in that a pump should be provided for each of the plurality of storage spaces formed by the sealed partition walls 112, so the partition walls 112 store the storage space of the cargo tank 11. Only one may be provided to be divided into two, and one storage space may be a fuel storage space 114 and the other storage space may be a cargo storage space 113.

As described above, in the present embodiment, to compensate for the portion in which the onboard liquefied gas loading space is reduced by the gap between the cargo tank 11 and the side shell plate 102, the gap of the IGC code is calculated using the sealed partition wall 112. By reducing the volume of the city, the entire volume of the cargo tank 11 itself can be expanded.

15, the gas processing system 1 according to the fourteenth embodiment of the present invention includes a cargo tank 11 in which the fuel storage unit 10 is mounted on board as described in the ninth to eleventh embodiments described above. ) And two or more independent pressure vessels, a fuel tank 12.

The cargo tank 11 stores liquefied gas at atmospheric pressure and is provided on board with an octagonal cross-section, but the dome 115 of the cargo tank 11 may be exposed to the upper deck 101 of the ship 100, the dome A moving passage 120 (piping area & access way) may be provided on the left or right side of the 115 in the longitudinal direction of the ship 100. The movement passage 120 shown in the drawings means a certain area in which the movement passage 120 is installed, not the movement passage 120 itself, and in this specification, the movement passage 120 is accessed by a sailor to access each facility. It is an access way, and a piping area through which the main line passes, meaning a space that should not interfere with other components.

The fuel tank 12 of the fuel storage unit 10 may be provided on the upper deck 101 instead of on board, and interference with the moving passage 120 may be a problem. Therefore, the fuel tank 12 is provided with a first fuel tank 12 between the moving passage 120 and the outer shell plate 102 on one side (portion side in the figure) where the moving passage 120 is provided in the upper deck 101. On the other hand, the second fuel tank 12 may be provided between the dome 115 and the side shell plate 102 on the opposite side (right side in the figure) of the one side where the movement passage 120 is provided in the upper deck 101. have.

At this time, the first fuel tank 12, the distance from the dome 115 compared to the second fuel tank 12 is formed larger, the area where the first fuel tank 12 is installed is the second fuel tank 12 ), the first fuel tank 12 may have a smaller volume than the second fuel tank 12 in order to resolve interference with the movement passage 120.

For example, the first fuel tank 12 is a high-pressure fuel tank 12a that stores liquefied gas at a critical pressure or higher to suppress the generation of evaporated gas at room temperature, and the second fuel tank 12 stores the liquefied gas below a critical pressure. It may be a low pressure fuel tank (12b) to be stored. In this case, the first fuel tank 12 may have a smaller volume than the second fuel tank 12 and a large outer wall, and may have a greater density than the second fuel tank 12.

In this way, while providing a plurality of fuel tanks 12 and placing them asymmetrically, in the case of LPG (propane 1.8 kg/m3, 2.4 kg/m3) having a density greater than that of LNG (0.65 kg/m3), one is placed on the upper deck 101 This is because when only the fuel tank 12 is provided, the hull stability is a problem because the right and left balance cannot be balanced.

That is, in this embodiment, in order to balance the left and right of the vessel 100, the fuel tank 12 is disposed on the left and right sides of the upper deck 101 based on the dome 115, but the high-pressure fuel tank 12a having a relatively small size. (First fuel tank 12) may be disposed outside the left and right directions of the movement passage 120.

At this time, the first fuel tank 12 may be disposed at a position that is not projected on the upper surface of the cargo tank 11 in the vertical direction, and the second fuel tank 12 is disposed on the upper surface of the cargo tank 11 in the vertical direction. It can be provided at the projected position. This is because the first fuel tank 12 is disposed at a position closer to the side shell plate 102 than the dome 115 to avoid interference with the movement passage 120.

As described above, in the present embodiment, when two or more fuel tanks 12 are provided on the upper deck 101, the left and right balance of the ship 100 is ensured while interference with the movement passage 120 is not made, and the ship 100 It can reduce the fatal rolling.

16 is a conceptual view of a ship to which the gas treatment system according to the fifteenth embodiment of the present invention is applied, and FIG. 17 is a front sectional view of a ship to which the gas treatment system according to the fifteenth embodiment of the invention is applied.

16 and 17, in the gas processing system 1 according to the fifteenth embodiment of the present invention, the fuel storage unit 10 may include a fuel tank 12 separately from the cargo tank 11. , The fuel tank 12 is a stand-alone pressure vessel and can be mounted on board.

A plurality of cargo tanks 11 may be provided in three or four in the front-rear direction of the ship 100, the Aesop fuel tank 12, as shown in Figure 16, the rear of the plurality of cargo tanks 11 Can be placed on. That is, the fuel tank 12 is disposed at the rear of the rearmost cargo tank 11.

The fuel tank 12 may be disposed inside the engine room as shown in FIG. 16, or, unlike the drawing, may be disposed between the engine compartment front bulkhead 112 and the rearmost cargo tank 11 outside the engine room. Do.

The propulsion engine (E) may be a fuel-fuel engine (Duel-Fuel engine) that uses oil as fuel in addition to liquefied gas, and requires an oil tank 13 to store oil to be supplied to the propulsion engine (E).

If there is no fuel tank 12 described in the present embodiment, the oil tank 13 may be provided on the front partition 112 of the engine room in the engine room, but in the case of this embodiment, the fuel tank 12 as shown in FIG. ) Can be provided on the left and right of the oil tank (13).

That is, two or more longitudinal bulkheads 112 are provided above the bottom plate 103 in the interior of the engine room or in the space of the space between the engine compartment front bulkhead 112 and the rearmost cargo tank 11, and in the middle space, the fuel tank ( 12) is accommodated, the left and right spaces can be utilized as the oil tank 13 in which the oil is stored, the fuel tank 12 and the oil tank 13 may be disposed around the ballast tank 110.

At this time, the fuel tank 12 is a stand-alone pressure vessel, and may be a lattice type pressure vessel in order to have a shape capable of securing a maximum volume of liquefied gas while responding to various structural shapes such as an engine room.

As described above, in the present exemplary embodiment, the fuel tank 12 is disposed by utilizing the position where the oil tank 13 is provided, thereby sufficiently protecting the liquefied gas from external shock or the like while securing space in the upper deck 101. .

In addition to the above-described embodiments, the present invention encompasses all of the embodiments that occur by a combination of at least two or more of the above embodiments or a combination of at least one or more of the above embodiments and known techniques.

The present invention has been described in detail through specific examples, but it is for the purpose of specifically describing the present invention, and the present invention is not limited to this, and by those skilled in the art within the technical spirit of the present invention. It will be apparent that the modification or improvement is possible.

All simple modifications or changes of the present invention belong to the scope of the present invention, and the specific protection scope of the present invention will be clarified by the appended claims.

Claims

A storage tank for storing liquefied gas;

Propulsion engine using liquefied petroleum gas as fuel;

A fuel supply line for supplying liquefied gas from the storage tank to the propulsion engine; And

And a fuel recovery line for recovering excess liquid liquefied gas discharged from the propulsion engine,

The fuel supply line is provided with a high pressure pump and a heat exchanger provided upstream of the high pressure pump to change the temperature of the liquefied gas,

The heat exchanger, a liquefied petroleum gas carrier having a gas treatment system, characterized in that the heat exchange between the liquefied gas supplied from the storage tank to the propulsion engine and the liquefied gas recovered from the fuel recovery line.
The method of claim 1, wherein the heat exchanger,

A gas treatment system comprising a stream having a stream through which liquefied gas is supplied from the storage tank to the propulsion engine, a stream through which the liquefied gas is recovered from the fuel recovery line, and a stream through which a heat exchange medium flows. Liquefied petroleum gas carrier.
According to claim 1,

The fuel recovery line delivers liquid liquefied gas to the high pressure pump,

The heat exchanger is a liquefied petroleum gas carrier having a gas treatment system characterized in that the liquefied gas of the fuel recovery line is cooled with liquefied gas and a heat exchange medium supplied to the propulsion engine to flow into the high pressure pump in a liquid phase.
According to claim 1,

The fuel recovery line is provided with a pressure reducing valve for reducing the pressure of the liquid liquefied gas,

The heat exchanger, a liquefied petroleum gas carrier having a gas treatment system, characterized in that to cool the decompressed liquefied gas to flow into the high pressure pump in a liquid phase.
According to claim 4, In the fuel recovery line,

Liquefaction having a gas treatment system, which is provided between the heat exchanger and the high pressure pump, and a mixer is provided to mix the liquefied gas passing through the heat exchanger and the liquefied gas supplied from the storage tank and deliver it to the high pressure pump. Oil gas carrier.