KR20160044106A - A Treatment System Of Liquefied Gas - Google Patents

Abstract

The present invention relates to a treatment system of liquefied gas. The treatment system of liquefied gas comprise: an ethane storage tank to store ethane; a low-speed two-stroke low-pressure gas spray engine to receive the ethane from the ethane storage tank to supply thrust to an offshore floating structure; an evaporation gas compressor to pressurize ethane evaporation gas supplied from the ethane storage tank; and a fuel reforming device to increase a methane number of the ethane evaporation gas. The treatment system of liquefied gas comprises a system which treats ethane or liquefied gas using the low-speed two-stroke low-pressure gas spray engine in the offshore floating structure to minimize power consumption and efficiently compress the ethane or the liquefied gas to maximize energy utilization. The low-speed two-stroke low-pressure gas spray engine requires a small installation area to increase usable space of the offshore floating structure. A simple structure of the system improves reliability of drive and reduces installation costs. Also, the treatment system of liquefied gas comprises the fuel reforming device to use the ethane as propulsion fuel to efficiently use the ethane and flexibly select the propulsion fuel to efficiently use energy.

Description

Description of the Related Art A Treatment System Of Liquefied Gas

The present invention relates to a liquefied gas processing system.

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

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

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

In addition, when LNG is stored in a liquid state, some LNG is vaporized and boil off gas (BOG) is generated as heat penetration occurs in the tank. Such evaporation gas may cause problems in a liquefied gas processing system. In order to solve the problem by discharging the evaporation gas to the outside (in the past, the evaporation gas was simply discharged to the outside in order to lower the tank pressure by lowering the tank pressure), the problem was solved. However, . Therefore, recently, as a technique for efficiently processing evaporative gas, there has been utilized a method of re-liquefying the generated evaporative gas and supplying it to the engine. However, since sufficient evaporative gas is not consumed even in such a utilization, efficient utilization And the ongoing research and development is being carried out.

 Ship owners have been using the LNG-fueled MEGI engine to propel ships and have been able to cope effectively with the recent NOx emission regulations and environmental pollution prevention. However, the MEGI engine has a problem that the power consumption is large, the installation cost is considerably high, the system configuration is complicated, and the installation area is required because the engine driving demand pressure is as high as 300 bar.

Therefore, a low-speed two-stroke low-pressure injection engine (2sDF or XDF) has been developed and a fuel supply system using a low-speed two-stroke low-pressure injection engine has been developed.

In addition to the use of LNG as propellant fuel, mass production of US shale gas has been reflected in the market needs of propane fuel, and numerous research and development efforts have been made to use ethane as propellant fuel .

It is an object of the present invention to provide a system for supplying fuel to a ship using a low-speed two-stroke low-pressure injection engine, thereby reducing power consumption and providing sufficient space And to provide a liquefied gas processing system capable of securing the liquefied gas.

It is another object of the present invention to provide a liquefied gas processing system capable of using ethane and LNG together as a fuel so that the evaporated gas can be efficiently used and the propellant fuel can be flexibly selected.

It is also an object of the present invention to provide a liquefied gas processing system for preventing the waste of ethane and increasing the re-liquefaction efficiency by enabling the cold heat of the LNG to be used for re-liquefaction of ethane.

It is also an object of the present invention to provide a liquefied gas processing system which can be provided with a fuel reformer so that ethane can be used as a propellant fuel to enable flexible selection of propellant fuel.

A liquefied gas processing system according to an embodiment of the present invention includes: an ethane storage tank for storing ethane; A low-speed two-stroke low-pressure gas injection engine that receives the ethane from the ethane storage tank and supplies thrust to the floating structure of the sea; An evaporative gas compressor for pressurizing the ethane-evaporated gas supplied from the ethane storage tank; And a fuel reforming device for increasing methane gas of the ethane evaporation gas.

Specifically, the evaporative gas compressor includes: an evaporative gas first compressor that pressurizes the vaporized ethane to a low pressure and supplies the pressurized gas to the fuel reformer; And an evaporative gas second compressor that pressurizes the reformed ethane vapor to a pressure required by the low-pressure two-stroke low-pressure gas injection engine and supplies the pressurized gas to the low-speed two-stroke low-pressure gas injection engine.

Specifically, the apparatus further comprises a DFDE, wherein the fuel reformer can supply the reformed ethane vapor to the DFDE or to supply the reformed gas to the second gas compressor.

Specifically, a forced vaporizer for forcibly vaporizing the ethane stored in the ethane storage tank; And a phase separator for separating the phase of the vaporized ethane supplied from the forced vaporizer.

Specifically, DFDE; A vaporized ethane feed line connecting the ethane storage tank and the slow two stroke low pressure gas injection engine and including the phase separator, the evaporative gas compressor, and the fuel reformer; A liquefied ethane feed line connecting the ethane storage tank and the phase separator and having the forced vaporizer; A liquefied ethane return line connecting the phase separator and the ethane storage tank to return the liquid separated ethane to the ethane storage tank; And a vaporization ethane branch line connecting the reformer and the DFDE to supply the reformed ethane to the DFDE.

Specifically, the fuel reformer may supply the reformed ethane vapor to the DFDE or supply the reformed ethane vapor to the low-pressure two-stroke low-pressure gas injection engine.

Specifically, the ethane storage tank may be an independent tank.

Specifically, the evaporative gas first compressor is pressurized to a low pressure of 5 to 10 bar, and the evaporative gas second compressor is pressurized to 12 to 20 bar.

Specifically, the fuel reforming apparatus can reform the ethane-evaporated gas into MN80 to MN90.

The liquefied gas processing system according to the present invention comprises a system for treating an ocean floating structure with ethane or liquefied gas through a low pressure two stroke low pressure gas injection engine to minimize power consumption and enable efficient compression of ethane or liquefied gas The low-speed two-stroke low-pressure gas injection engine is able to maximize the energy utilization rate. The installation area of the low-pressure two-stroke low-pressure gas injection engine can enlarge the use space of the floating structure of the marine structure and simplify the structure of the system, It is effective.

Further, the liquefied gas processing system according to the present invention includes a fuel reforming device and a mixer to enable the use of ethane as a propellant fuel, thereby enabling efficient use of ethane, flexible selection of propellant fuel, There is an effect that it can be used efficiently.

Further, the liquefied gas processing system according to the present invention can reduce the size and weight of the fuel reformer by mixing the high methane-modified ethane with the LNG through the fuel reforming device, And the efficiency of the engine can be improved by improving the methane price of the fuel.

Further, the liquefied gas processing system according to the present invention further comprises a mixer and a re-liquefaction system to re-liquefy ethane and mixes generated flash gas and LNG to minimize the loss of ethane and effectively maintain the methane price .

In addition, the liquefied gas processing system according to the present invention can reduce the energy consumed in liquefying ethane by reducing the energy efficiency of the liquefaction cycle by using the cold heat of the LNG used as the propellant in the refrigerant cycle for re- There is an effect that can be maximized.

Further, the liquefied gas processing system according to the present invention further comprises an ethane-liquefied gas heat exchanger to recover the cold heat of the liquefied gas, so that the ethane-evaporated gas can be precooled before re-liquefaction or directly re-liquefied, The efficiency can be maximized.

1 is a conceptual diagram showing a liquefied gas processing system according to a first embodiment of the present invention.
2 is a conceptual diagram showing a liquefied gas processing system according to a second embodiment of the present invention.
3 is a conceptual diagram showing a liquefied gas processing system according to a third embodiment of the present invention.
4 is a conceptual diagram showing a liquefied gas processing system according to a fourth embodiment of the present invention.
5 is a conceptual diagram showing a liquefied gas processing system according to a fifth embodiment of the present invention.
6 is a conceptual diagram showing a liquefied gas processing system in which the fifth embodiment of the present invention is modified.

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

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

1, the liquefied gas processing system 1 according to the first embodiment of the present invention includes an ethane storage tank 10, a demander 11, a fuel reformer 12, a forced vaporizer 13, Gas compressor (14) and phase separator (15).

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

The ethane storage tank 10 stores ethane, and a plurality of the ethane storage tanks 10 may store ethane to transport a large amount of ethane. The ethane storage tank 10 may be in the form of a pressure tank, that is, an independent tank, since the ethane must be stored in a liquid state.

The ethane storage tank 10 may have a thermal insulation structure to store the cryogenic ethane having a boiling point of minus 89 degrees Celsius in a liquid state.

The ethane storage tank 10 may include a pump (not shown) provided inside the tank. The pump can supply the ethane stored in the ethane storage tank 10 to the forced vaporizer 13, which will be described later, and can be provided in a centrifugal manner.

In the first embodiment of the present invention, the vaporized ethane supply line 20, the liquefied ethane supply line 21, the liquefied ethane return line 22, and the vaporized ethane branch line 23 may be further included.

The vaporizing ethane supply line 20 can supply the ethane by connecting the ethane storage tank 10 and the consumer 11 and supplies the ethanol to the phase separator 15, the evaporative gas compressor 14, the fuel reformer 12, .

The liquefied ethane feed line 21 connects the ethane storage tank 10 and the phase separator 15 and can supply the vaporized ethane to the phase separator 15 by providing the forced vaporizer 13 to be described later.

The liquefied ethane return line 22 may connect the phase separator 15 and the liquefied gas storage tank 10 to return the unevaporated ethane in the phase separator 15 to the liquefied gas storage tank 10.

The vaporized ethane branch line 23 connects the fuel reformer 12 and the DFDE 112 to be described later and can supply the reformate vapor from the fuel reformer 12 to the DFDE 112.

At this time, the vaporized ethane supply line 20, the liquefied ethane supply line 21, the liquefied ethane return line 22, and the vaporized ethane branch line 23 are supplied with the vaporized ethane supply valve, the liquefied ethane supply valve, A vaporizing ethane branching valve (not shown) is provided, and the supply amount of the ethane-evaporated gas or the liquefied ethane can be adjusted according to the opening degree control of each of the valves.

The consumer 11 is driven by using ethane stored in the ethane storage tank 10 as fuel. That is, the customer 11 needs all of the devices and mechanisms that require ethane and are driven using the ethane as a raw material. However, in the embodiment of the present invention, the customer 11 may be a low-speed two-stroke low-pressure gas injection engine 111, a heterogeneous fuel engine (DFDE) 112, and a gas combustion device (not shown).

The low-pressure two-stroke low-pressure gas injection engine 111 receives the ethane from the ethane storage tank 10 and supplies thrust to the floating structure (not shown). The low-speed two-stroke low-pressure gas injection engine 111 is connected to the piston as the piston (not shown) inside the cylinder (not shown) reciprocates by the combustion of the ethane gas, liquefied gas, A crankshaft (not shown) is rotated, and a shaft (not shown) connected to the crankshaft can be rotated. Therefore, as the propeller (not shown) connected to the shaft rotates when driving the low-speed two-stroke low pressure gas injection engine 111, the floating structure of the ocean can be advanced or reversed.

The low-speed two-stroke low-pressure gas injection engine 111 in the embodiment of the present invention can be a 2s DF engine (XDF engine) developed by wartsila, and can be driven according to an Otto cycle have.

That is, the low-speed two-stroke low-pressure gas injection engine 111 compresses the air-fuel mixture supplied to the cylinder to the top dead center at the moment of ignition by the ignition fuel (Pilot Fuel) - The fuel mixer is completely burned so that explosive power is generated. At this time, the air-fuel mixture mass ratio may be in the form of a Lean burn engine which may be in a lean state less than 14.7: 1.

In this case, HFO (Heavy Fuel Oil) or MDO (Marine Diesel Oil) is used as the ignition fuel, and the ratio of the ignition fuel to the high-pressure gas is about 1:99.

The low-pressure two-stroke low-pressure gas injection engine 111 is capable of generating power by supplying liquefied gas of 8 to 20 bar (preferably, 10 bar), and the state of the supplied ethane is supplied to the low- It may vary depending on the required state.

In the embodiment of the present invention, a thrust is generated through a MEGI engine (not shown) in a large-sized ship (not shown). However, in the embodiment of the present invention, ). ≪ / RTI >

The MEGI engine requires a high pressure of about 200 bar to about 300 bar, which is necessary for driving the supply fuel, and requires a considerable amount of electric power to be consumed, which is about 210KW to about 220KW (about 215KW) for driving.

On the other hand, the low-speed two-stroke low-pressure gas injection engine 111 has a consumption power for driving at a low pressure of 8 to 20 bar (preferably 10 bar) ), It is possible to reduce much power compared with the MEGI engine.

Further, the MEGI engine has a problem that the gas supply system (not shown) accompanying the MEGI engine is very complicated and takes up a lot of space in order to generate the pressure required by the MEGI engine because the driving pressure is extremely high.

The low-speed two-stroke low-pressure gas injection engine 111 is advantageous in that the fuel supply system is very simple and the space occupied by the low-pressure two-stroke low-pressure gas injection engine 111 is low because the driving pressure is low.

The heterogeneous fuel engine (DFDE) 112 may be an engine for generating power or other power. The heterogeneous fuel engine 112 can be selectively supplied with liquefied gas or fuel oil (oil) without being mixed with ethane and fuel oil. This is to prevent the mixture of two materials having different combustion temperatures from being mixed, thereby preventing the efficiency of the engine from deteriorating.

The gas combustion device refers to a device that burns the ethane-evaporated gas to consume the excess ethane-evaporated gas. This is a well-known device and a detailed description thereof will be omitted.

The fuel reforming device 12 increases the methane price of the ethane gas. Specifically, the fuel reforming apparatus 12 receives the ethane evaporation gas from the evaporation gas first compressor 141, which will be described later, and modifies the ethane evaporation gas to convert the methane gas to the MN 80 to MN 90 (preferably, MN 85) .

The fuel reforming apparatus 12 is provided on the vaporizing ethane supply line 20 and supplies methane gas to the DFDE 112 or the low speed 2 The low-pressure gas injection engine 111 can supply the reformed ethane vapor.

Here, the fuel reforming apparatus 12 can supply and reform the ethane evaporation gas pressurized from the evaporation gas first compressor 141 to 5 bar to 10 bar (preferably 8 bar) 2 compressor 142 so that the low-pressure two-stroke low-pressure gas injection engine 111 uses the reformed ethane vapor gas pressurized to 12 to 20 bar (preferably 15 bar).

Conventionally, an LNG fuel supply system that drives an engine using LNG as thrust fuel has been used in an LNG carrier carrying Liquefied Natural Gas. LNG has been attracting attention as a propellant because it is inexpensive, its reserves are abundant, and it does not pollute the environment. Ethane, on the other hand, was expensive to produce and was not used as propellant because of its high production costs and high price.

Unlike the conventional situation, the shale gas which has not been developed due to the technical constraints has been actively developed and produced by the development of science. The ethane is the largest portion of the shale gas, and mass production of the shale gas The production of ethane is increasing rapidly.

Therefore, as the demand for ethane carriers for transporting these ethane is soaring, the price competitiveness of the ethane has increased, and attempts have been made to use ethane as propellant fuel. Propane engines using ethane as fuel have also been commercialized. Applicants have developed a system for using ethane as propellant fuel.

However, when the ethane is used in the low-pressure two-stroke low-pressure gas injection engine 111, the methane price may be low, which may cause problems in driving. Therefore, in the embodiment of the present invention, the fuel reforming apparatus 12 is additionally provided to increase the methane charge of the methane to the low-pressure two-stroke low-pressure gas injection engine 111 so that the low-speed two- So that sufficient power can be generated even though ethane is used.

As a result, in the embodiment of the present invention, the low-speed two-stroke low-pressure gas injection engine 111 can use ethane as fuel, thereby increasing the elasticity of fuel selection and effectively reducing the driving power consumption, The reliability is maximized, and the installation cost is saved.

The forced vaporizer (13) forcibly vaporizes the ethane stored in the ethane storage tank (10). Specifically, the forced vaporizer 13 is provided on the liquefied ethane feed line 21 to supply liquid ethane from a pump provided in the ethane storage tank 10, forcibly vaporize it, ).

The forced vaporizer 13 is capable of vaporizing liquefied ethane and is capable of vaporizing liquefied ethane when the amount of ethane evaporated gas required by the consumer 11 is smaller than the amount of ethane evaporated gas normally consumed by the consumed place 11, The liquefied ethane can be further vaporized and supplied to the customer 11 when the amount of ethane evaporated gas which is consumed by the customer 11 is higher than the amount of ethane evaporated gas normally consumed by the customer 11.

The evaporative gas compressor (14) pressurizes the ethane vapor generated in the ethane storage tank (10). Specifically, the evaporative gas compressor 14 is provided on the vaporized ethane supply line 20 and can supply and pressurize the vaporized ethane vapor gas from the phase separator 15, which will be described later.

The evaporation gas compressor 14 includes an evaporation gas first compressor 141 that pressurizes the vaporized ethane gas to a low pressure and supplies it to the fuel reforming apparatus 12 and a low pressure two stroke low pressure gas injection engine 111 Pressure low-pressure gas injection engine 111. The low-pressure two-stroke low-pressure gas injection engine 111 is provided with an evaporation gas second compressor 142 that pressurizes the low-

The evaporated gas first compressor 141 is provided between the phase separator 15 and the fuel reforming apparatus 12 on the vaporized ethane feed line 20 and feeds the vaporized ethane gas supplied from the phase separator 15 to 5 bar To 10 bar (preferably 8 bar) to supply the fuel to the fuel reformer 12.

The second evaporator gas compressor 142 is provided between the fuel reforming device 12 and the low-pressure two-stroke low-pressure gas injection engine 111 on the vaporized ethane feed line 20 and is supplied from the fuel reformer 12 The reformed ethane vapor gas may be further pressurized to 12 to 20 bar (preferably 15 bar) and supplied to the low-speed two-stroke low-pressure gas injection engine 111.

The evaporation gas compressor 14 is separated into an evaporation gas first compressor 141 and an evaporation gas second compressor 142 so that a fuel reforming process is performed between the evaporation gas first compressor 141 and the evaporation gas second compressor 142 The apparatus 12 is provided and the reforming apparatus 12 supplies the modified ethane vapor gas to the DFDE 112 or the low-speed two-stroke low-pressure gas injection engine 111, Pressure low-pressure gas injection engine 111, so that it is possible to effectively use the ethane-evaporated gas and to prevent waste of the ethane-evaporated gas.

The phase separator 15 separates the vaporized ethane supplied from the forced vaporizer 13. Specifically, the phase separator 15 is provided between the ethane storage tank 10 and the evaporative gas first compressor 141 on the vaporized ethane feed line 20 to generate the ethane vapor from the ethane storage tank 10 Is connected to the forced vaporizer (13) by the liquefied ethane feed line (21), and the vaporized ethane gas is supplied from the forced vaporizer (13) to separate the phase of the ethane gas into vapor or liquid, The gas is supplied to the first evaporator 141 and the unburned ethane gas, that is, the liquid ethane gas, can be returned to the ethane storage tank 10.

At this time, the phase separator 15 is connected to the ethane storage tank 10 by the liquefied methane return line 22 to return the liquid ethane gas to the ethane storage tank 10 through the liquefied methane return line 22 .

As described above, the liquefied gas processing system 1 according to the present invention includes a system for processing ethane through a low-speed two-stroke low-pressure gas injection engine 111 on a floating structure of a marine structure, thereby reducing the power consumption And the low-speed two-stroke low-pressure gas injection engine 111 has a small installation area, so that the use space of the marine floating structure can be enlarged, and the system configuration is simple, so that the reliability of driving is improved and the installation cost is saved. have.

In addition, the liquefied gas processing system 1 according to the present invention is provided with the fuel reforming device 12 so as to be able to use ethane as propellant fuel, thereby enabling efficient use of ethane, It is possible to efficiently use the energy.

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

2, the liquefied gas processing system 2 according to the second embodiment of the present invention includes an ethane storage tank 10, a demander 11, a fuel reforming device 12, a forced vaporizer 13, A gas compressor 14, a phase separator 15, a mixer 16, a liquefied gas storage tank 30, a pump 31, and a liquefied gas heat exchanger 32.

Each configuration except for the mixer 16, the liquefied gas storage tank 30, the pump 31 and the liquefied gas heat exchanger 32 in the second embodiment of the present invention is the same as that of the liquefied gas according to the first embodiment of the present invention The same reference numerals are used for the constitution and the processing in the processing system 1, but they are not necessarily referred to the same configurations.

In the second embodiment of the present invention, a liquefied gas supply line 24 may be further included.

The liquefied gas supply line 24 connects the liquefied gas storage tank 10 and the DFDE 112 and may include a pump 31, a liquefied gas heat exchanger 32 and a mixer 16 to be described later.

In the second embodiment of the present invention, the liquefied gas supply line 24 and the vaporized ethane supply line 20 are crossed in the mixer 16 to connect the DFDE 112 and the low-pressure two-stroke low-pressure gas injection engine 111 The liquefied gas supply line 24 and the vaporized ethane supply line 20 downstream of the mixer 16 connected to the DFDE 112 or the low-pressure two-stroke low-pressure gas injection engine 111 are provided with a gas- Only a mixture of liquefied gases can flow, or only liquefied gases that are only ethane can flow.

At this time, the liquefied gas supply line 24 is provided with a liquefied gas supply valve (not shown), and the supply amount of the liquefied gas can be adjusted according to the opening degree of the liquefied gas supply valves.

In the second embodiment of the present invention, a mixer 16 may be additionally provided in the vaporizing ethane feed line 20, unlike in the first embodiment of the present invention, and the consumer 11 mixes ethane and LNG And the selective supply to the DFDE 112 or the low-speed two-stroke low-pressure gas injection engine 111 can be performed in the mixer 16, and not in the fuel reformer 12. [

The mixer 16 mixes the liquefied gas supplied from the liquefied gas storage tank 30 with the ethane evaporated gas modified in the fuel reformer 12.

Specifically, the mixer 16 mixes the fuel reforming device 12 and the evaporative gas second compressor (not shown) on the vaporized ethane feed line 20 at a position where the vaporized ethane feed line 20 and the liquefied gas feed line 24 intersect 142 and the liquefied gas heat exchanger 32 and the DFDE 112 on the liquefied gas supply line 24 so that the liquefied gas vaporized from the liquefied gas heat exchanger 32 is reformed from the fuel reforming apparatus 12, It is possible to mix the vaporized liquefied gas with the modified ethane vaporized gas.

The mixer 16 mixes the vaporized liquefied gas with the modified ethane vapor to supply it to the DFDE 112 or to the evaporative gas second compressor 142 to further pressurize the vapor at a pressure of 8 bar to 20 bar, So that the mixed fuel can be used in the gas injection engine 111.

Thus, in the second embodiment of the present invention, the vaporized liquefied gas and the modified ethane-evaporated gas are mixed with each other and supplied to the demand place 11, whereby the methane price of the fuel can be effectively improved and the driving efficiency of the demand place 11 can be improved There is an effect that can be maximized.

Further, in the second embodiment of the present invention, it is possible to selectively supply the fuel to the DFDE 112 or the low-speed two-stroke low-pressure gas injection engine 111 in the mixer 16, This has the effect of optimizing the energy use of floating structures in the ocean.

The mixer 16 may mix the vaporized liquefied gas and the modified ethane vapor until the methane value is on the order of MN 80 to MN 90 (preferably MN 85). That is, in the second embodiment of the present invention, not only the fuel reformer 12 but also the mixer 16 can increase the methane price of the fuel, thereby reducing the capability of the fuel reformer 12 to process, The size and weight of the fuel reforming apparatus 12 can be effectively reduced.

The liquefied gas storage tank 30 stores the liquefied gas, and the liquefied gas may be liquefied natural gas, that is, LNG. The liquefied gas storage tank 30 may have the form of a pressure tank for storing the liquefied gas in a liquid state. That is, the liquefied gas storage tank 30 may be in the form of an independent tank.

The liquefied gas storage tank 30 includes an outer tank (not shown), an inner tank (not shown), and a heat insulating portion (not shown). The outer tank is a structure that forms the outer wall of the liquefied gas storage tank 10, and may be formed of steel, and may have a polygonal cross section.

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

The tanks may be made of stainless steel and designed to withstand pressures from 1 bar to 10 bar (6 bar, for example). The reason why the inner tank is designed to withstand such a constant pressure is that the inner pressure of the inner tank may be increased because the liquefied gas contained in the inner tank is evaporated to generate the evaporative gas.

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

The heat insulating portion is provided between the inner tank and the outer tank and can prevent the external heat energy from being transmitted to the inner tank. At this time, the heat insulating portion may be in a vacuum state. By forming the thermal insulation in a vacuum, the liquefied gas storage tank 30 can withstand higher pressures more efficiently than a conventional tank. For example, the liquefied gas storage tank 10 can sustain a pressure of 5 to 20 bar through the vacuum insulation.

As described above, in the second embodiment of the present invention, the use of the pressure tank type liquefied gas storage tank 30 provided with the adiabatic part of vacuum type between the outer tanks and the inner tank makes it possible to minimize the generation of the evaporated gas, It is possible to prevent a problem such as breakage of the liquefied gas storage tank 30 even if it is increased.

The pump 31 may be provided on the liquefied gas supply line 24 to pressurize the liquefied gas in the liquefied gas storage tank 30. At this time, the pump 31 may be provided inside the liquefied gas storage tank 30 and may be of a locking type.

Specifically, the pump 31 is provided between the liquefied gas storage tank 30 and the liquefied gas heat exchanger 32, which will be described later, on the liquefied gas supply line 24, and the liquefied gas stored in the liquefied gas storage tank 30 To the liquefied gas heat exchanger (32).

The pump 31 can supply a sufficient amount of liquefied gas to the liquefied gas heat exchanger 32 and can extract the liquefied gas from the liquefied gas storage tank 30 to pressurize the liquefied gas within a few to several tens of bars have. The liquefied gas through the pump 31 can be pressurized from 1 bar to 25 bar, preferably 10 bar.

The pump 31 may pressurize the liquefied gas discharged from the liquefied gas storage tank 30 to slightly increase the pressure and the temperature and the liquefied gas pressurized by the pump 31 may still be in a liquid state. Therefore, the pump 31 can supply the pressurized liquefied gas to the liquefied gas heat exchanger 32 to vaporize the liquefied gas.

The liquefied gas heat exchanger (32) can heat and vaporize the liquefied gas pressurized from the pump (31). Specifically, the liquefied gas heat exchanger 32 is provided between the pump 31 and the mixer 16 on the liquefied gas supply line 24 and supplies the pressurized liquefied gas from the pump 31 to the mixer 16 ).

The liquefied gas heat exchanger 32 can vaporize the liquefied gas by keeping the pressure of the liquefied gas pressurized by the pump 31 intact.

As described above, the liquefied gas processing system 2 according to the present invention includes the system for processing the ethane or the liquefied gas through the low-speed two-stroke low-pressure gas injection engine 111 to the marine floating structure (not shown) The low-speed two-stroke low-pressure gas injection engine (111) can increase the use space of marine floating structures because the installation area is small, and the system The reliability of the driving is improved and the installation cost is saved.

Further, the liquefied gas processing system 2 according to the present invention can be realized by mixing the high methane-modified ethane with the LNG through the fuel reforming device 12 and the mixer 16, And the weight can be reduced, thereby securing the space and reducing the installation cost, and it is possible to improve the efficiency of the engine by improving the methane price of the fuel.

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

3, the liquefied gas processing system 3 according to the third embodiment of the present invention includes an ethane storage tank 10, a customer 11, an evaporative gas compressor 14, a mixer 16, An apparatus 17, a liquefied gas storage tank 30, a pump 31, and a liquefied gas heat exchanger 32.

Each configuration except for the evaporative gas compressor 14, the mixer 16, and the remelting device 17 in the third embodiment of the present invention is the same as that of the liquefied gas processing system 1 according to the first and second embodiments of the present invention , And (2), the same reference numerals are used for the sake of convenience and the same reference numerals are not used for the sake of convenience.

In the third embodiment of the present invention, an ethane circulation line 20a may be further included.

The ethane circulation line 20a connects the ethane storage tank 10 and the refill liquor device 17 to be described later to supply the ethane evaporation gas generated in the ethane storage tank 10 to the refueling device 17, The liquefied ethane-evaporated gas in the liquefier 17 can be returned to the ethane storage tank 10, and the evaporative gas compressor 14 can be provided.

At this time, an ethane circulation valve (not shown) is provided in the ethane circulation line 20a, and the supply amount of the ethane evaporation gas or the re-liquefied ethane evaporation gas can be adjusted according to the opening degree control of the ethane circulation valves.

In addition, in the third embodiment of the present invention, the vaporized ethane supply line 20 differs from the first and second embodiments of the present invention in that the ethane storage tank 10 on the ethane circulation line 20a, (Low-pressure two-stroke low-pressure gas injection engine 111), and may be provided with a mixer 16.

In the third embodiment of the present invention, the mixed fuel supplied from the mixer 16, which is provided between the mixer 16 and the DFDE 112 on the liquefied gas supply line 24, is supplied to the DFDE 112 And the liquefied gas control valve 241 regulates the pressure to a required pressure.

The liquefied gas control valve 241 may take the form of flow rate control or pressure control.

The evaporative gas compressor 14 may be provided between the ethane storage tank 10 and the refueling device 17 on the ethane circulation line 20a to pressurize the ethane evaporation gas. Specifically, the evaporative gas compressor 14 can pressurize the ethane vapor with the pressure required by the refueling device 17 so that the refueling device 17 can effectively re-liquefy the ethane-evaporated gas.

The mixer 16 mixes the flash gas generated in the remelting device 17 with the liquefied gas supplied from the liquefied gas storage tank 10 and supplies the mixed fuel to the low-speed two-stroke low-pressure gas injection engine 111 .

Specifically, the mixer 16 is provided between the liquefied gas heat exchanger 32 on the liquefied gas supply line 24 and the DFDE 112, and at the same time, the vaporized ethane supply line 20 branched from the ethane circulation line 20a. So that the flash gas generated in the remelting device 17 and the liquefied gas supplied from the liquefied gas storage tank 10 can be mixed.

The mixer 16 can mix the flash gas generated in the remelting device 17 and the methane value of the liquefied gas supplied from the liquefied gas storage tank 30 until MN 80 to MN 90, Can be selectively supplied to the DFDE 112 or the low-speed two-stroke low-pressure gas injection engine 111.

As described above, in the third embodiment of the present invention, the mixer 16 mixes the flash gas generated in the liquefaction device 17 with the liquefied gas and supplies it to the customer 11, There is an effect that the loss of ethane can be minimized.

In addition, by using a mixture of ethane gas and LNG, the methane charge of the fuel is increased and the driving efficiency of the customer 11 is increased, so that the energy use of the floating structure of the ocean can be efficiently performed.

The re-liquefier 17 re-liquefies the ethane-evaporated gas generated in the ethane storage tank 10. Specifically, the liquefaction device 17 is provided between the evaporative gas compressor 14 and the ethane storage tank 10 on the ethane circulation line 20a, and the evaporated gas compressed from the evaporative gas compressor 14 The liquefied ethane-evaporated gas can be returned to the ethane storage tank 10 after the liquefaction is performed.

The liquefaction device 17 is capable of returning the re-liquefied ethane gas to the ethane storage tank 10, and the flash gas generated while re-liquefying it can be supplied to the mixer 16.

As described above, the liquefied gas processing system 3 according to the present invention includes a system for treating the marine floating structure with the ethane or liquefied gas through the low-speed two-stroke low-pressure gas injection engine 111, thereby minimizing power consumption It is possible to maximize the energy utilization rate and the low-speed two-stroke low-pressure gas injection engine 111 can expand the use space of the floating structure by the small installation area, and the system configuration is simple So that the reliability of the driving is improved and the installation cost is saved.

Further, the liquefied gas processing system 3 according to the present invention further includes a mixer 16 and a refueling device 17 to re-liquefy ethane and mix the generated flash gas and LNG to minimize the loss of ethane And it is effective to keep methane efficiently.

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

4, the liquefied gas processing system 4 according to the fourth embodiment of the present invention includes an ethane storage tank 10, a customer 11, an evaporative gas compressor 14, a re-liquefier 17, A liquefied refrigerant apparatus 171, a liquefied gas storage tank 30, a pump 31, and a liquefied gas heat exchanger 32.

In the fourth embodiment of the present invention, each configuration except for the liquefaction device 17, the liquefied refrigerant device 171 and the liquefied gas heat exchanger 32 is the same as the liquefied gas according to the first to third embodiments of the present invention The same reference numerals are used for the constitution and convenience in the processing systems 1 to 3, but they are not necessarily referred to as the same configurations.

In the fourth embodiment of the present invention, the liquefied gas branch line 24a may be further included.

The liquefied gas branch line 24a branches between the liquefied gas heat exchanger 32 and the low pressure two stroke low pressure gas injection engine 111 on the liquefied gas supply line 24 to connect the DFDE 112 to the DFDE 112 ). ≪ / RTI >

The liquefied gas branch line 24a is provided between the liquefied gas heat exchanger 32 and the DFDE 112 on the liquefied gas branch line 24a and the pressure of the mixed fuel supplied from the liquefied gas heat exchanger 32 And a liquefied gas control valve 241 for controlling the pressure of the DFDE 112 to a required pressure.

The liquefied gas control valve 241 may take the form of flow rate control or pressure control.

The re-liquefier 17 re-liquefies ethane-evaporated gas generated in the ethane storage tank 10. The re-liquefier 17 can be connected to the re-liquefied refrigerant system 171 to be supplied with a cold source, which is cooled by the heat exchange between the ethane evaporative gas and the refrigerant in the re-liquefier refrigerant system 171 The refrigerant in the re-liquefied refrigerant device 171 can be made by heating.

The mechanism in which the re-liquefier 17 is supplied with the cool source will be described later in the re-liquefied refrigerant system 171.

The re-liquefying refrigerant system 171 is connected to the re-liquefier 17 to supply the refrigerant to the liquefier 17 and to the liquefied gas heat exchanger 32 to supply the refrigerant from the liquefied gas heat exchanger 32 It is supplied.

That is, the re-liquefying refrigerant device 171 is connected to the liquefaction device 17 and the liquefied gas heat exchanger 32 so that the liquefaction device 17 can be switched from the liquefied gas supplied to the liquefied gas heat exchanger 32 The refrigerant is indirectly supplied through the refrigerant of the liquefied refrigerant system 171 and the liquefied gas heat exchanger 32 is connected to the liquefied refrigerant system 171 by the heat source from the ethane- It can be indirectly supplied through the refrigerant.

Here, the refrigerant in the re-liquefied refrigerant device 171 can be heat-exchanged secondarily with the ethane-evaporated gas after primarily exchanging heat with the liquefied gas. The liquefied gas is heated by the heat exchange of the refrigerant in the liquefied gas and the liquefied refrigerant device 171, the refrigerant is cooled, the evaporated gas is cooled by the heat exchange between the ethane evaporated gas and the refrigerant in the liquefied refrigerant device 171, .

The re-liquefied refrigerant device 171 is connected to the re-liquefier device 17 to provide a re-liquefied refrigerant circulation line 25 for circulating the refrigerant of the re-liquefied refrigerant device 171 to the re-liquefier device 17, And a cold source circulation line 26 connected to the refrigerant circulation line 32 to circulate the refrigerant in the re-liquefied refrigerant device 171 to the liquefied gas heat exchanger 32.

The re-liquefied refrigerant circulation line 25 is connected to the re-liquefied refrigerant return line 251 for returning the refrigerant of the re-liquefied refrigerant device 171 from the liquefaction device 17 to the liquefied refrigerant device 171, And a re-liquefied refrigerant supply line (252) for supplying the refrigerant of the first heat exchanger (171) to the re-liquefier (17).

The cold source circulation line 26 is connected to the cold source supply line 261 for supplying the refrigerant of the remanufactured refrigerant apparatus 171 to the liquefied gas heat exchanger 32 and the refrigerant of the liquefied refrigerant apparatus 171 to the liquefied gas heat exchanger 32 to return to the liquefied refrigerant system 171.

The re-liquefied refrigerant system 171 includes a first refrigerant circulating through the re-liquefier 17 and the re-liquefiered refrigerant system 171 through the re-liquefied refrigerant circulation line 25; And a second refrigerant circulating through the liquefied gas heat exchanger 32 and the liquefied refrigerant system 171 through the cold source circulation line 26 to provide a cold source supply mechanism for the liquefaction device 17 by the additional heat exchange of the two refrigerants Liquefaction refrigerant circulation line 25 and the cold source circulation line 26 may be connected to perform a cold source supply mechanism to the liquefaction device 17 as a single coolant.

Here, the additional heat exchange between the first refrigerant and the second refrigerant indicates that the first refrigerant is supplied with the cold source from the second refrigerant, or the second refrigerant is supplied with the heat source from the first refrigerant.

Hereinafter, the heat exchange mechanism between the re-liquefied refrigerant device 171, the liquefaction device 17 and the liquefied gas heat exchanger 32 will be described in detail. However, in the present technology, since the liquefaction device 17 and the liquefied gas heat exchanger 32 form a complementary relationship with each other, they are described from the viewpoint of efficiency improvement of the liquefaction device 17 for convenience of description.

When the re-liquefied refrigerant system 171 performs the heat exchange mechanism with two refrigerants, the second refrigerant of the re-liquefied refrigerant system 171 is supplied to the liquefied gas heat exchanger 32 through the cold source supply line 261, (The second refrigerant is cooled, the liquefied gas is heated and vaporized), the heat-exchanged second refrigerant is returned to the re-liquefied refrigerant system 171 via the cold source return line 262 and the heat exchanged with the first refrigerant (The second refrigerant is heated and the first refrigerant is cooled)

The first refrigerant heat exchanged with the second refrigerant is supplied to the liquefaction device 17 through the re-liquefied refrigerant supply line 252 to heat-exchange with the ethane-evaporated gas (the first refrigerant is heated and the ethane-evaporated gas is cooled Re-liquefied) The heat-exchanged first refrigerant is returned to the liquefied refrigerant system 171 via the re-liquefied refrigerant return line 251 and exchanges heat with the second refrigerant again (the first refrigerant is cooled and the second refrigerant is heated being)

When the re-liquefied refrigerant system 171 performs the heat exchange mechanism with one refrigerant, the refrigerant in the re-liquefied refrigerant system 171 is supplied to the liquefied gas heat exchanger 32 through the cold source supply line 261, (The refrigerant is cooled and the liquefied gas is heated and vaporized) is returned to the liquefied refrigerant system 171 via the cold source return line 262 and the liquefied refrigerant connected to the cold source return line 262 And is supplied directly to the refueling device 17 through the supply line 252.

The refrigerant is supplied to the re-liquefier 17 via the re-liquefied refrigerant supply line 252 and exchanges heat with the ethane evaporated gas (the refrigerant is heated and the ethane evaporated gas is cooled and re-liquefied) The refrigerant is returned directly to the liquefied refrigerant system 171 through the refrigerant return line 251 and directly supplied to the liquefied gas heat exchanger 32 through the refrigerant supply line 261 connected to the re-liquefied refrigerant return line 251. The refrigerant supplied to the gas heat exchanger 32 repeats heat exchange with the liquefied gas)

Thus, the liquefaction device 17 has the effect of recovering the cold heat of the liquefied gas to improve the liquefaction efficiency. The liquefied gas heat exchanger 32 recovers the heat of the ethane-evaporated gas to improve the heat exchange efficiency There is an effect that the energy required for driving the liquefaction device 17 and the liquefied gas heat exchanger 32 can be saved.

That is, the redistribution device 17 and the liquefied gas heat exchanger 32 have a mutually complementary relationship by exchanging the cold source and the heat source with each other.

The liquefied gas heat exchanger (32) heats the liquefied gas supplied from the pump (31) and supplies it to the customer (11). The liquefied gas heat exchanger (32) can receive the heat source necessary for heating the liquefied gas from the liquefied refrigerant device (171).

The liquefied gas heat exchanger 32 is connected to the re-liquefied refrigerant device 171 to heat-exchange the liquefied gas with the refrigerant in the liquefied refrigerant device 171, the liquefied gas to be heated, and the refrigerant to be cooled. The cool source or heat source exchange mechanism between the liquefied gas heat exchanger 32 and the liquefied refrigerant device 171 is replaced with the content described in the liquefied refrigerant device 171.

As described above, the liquefied gas processing system 4 according to the present invention includes a system for processing ethane or liquefied gas through a low-speed two-stroke low-pressure gas injection engine 111 to a floating structure of a marine structure, thereby minimizing power consumption, Or the liquefied gas can be efficiently compressed to maximize the energy utilization rate. The low-speed two-stroke low-pressure gas injection engine 111 has a small installation area and can enlarge the use space of the floating structure of the marine structure. The driving reliability is improved and the installation cost is saved.

In addition, the liquefied gas processing system 4 according to the present invention can reduce the energy consumed in the liquefying of ethane by using the cold heat of the LNG used as the propellant fuel in the refrigerant cycle for re-liquefaction of ethane, It is possible to maximize the energy efficiency.

FIG. 5 is a conceptual view showing a liquefied gas processing system according to a fifth embodiment of the present invention, and FIG. 6 is a conceptual diagram showing a liquefied gas processing system modified from the fifth embodiment of the present invention.

5 and 6, the liquefied gas processing systems 5a and 5b according to the modified examples of the fifth and fifth embodiments of the present invention include an ethane storage tank 10, a customer 11, A liquefied gas storage tank 30, a pump 31, a liquefied gas heat exchanger 32 and an ethane-liquefied gas heat exchanger 33. The compressor 14, the liquefaction device 17, the liquefied gas storage tank 30,

In the modified examples of the fifth and fifth embodiments of the present invention, each configuration except for the ethane-liquefied gas heat exchanger 33 is the same as that of the liquefied gas processing system 1 - 4), the same reference numerals are used for the sake of convenience and the same reference numerals are not used for the sake of convenience.

In a modification of the fifth embodiment of the present invention, it may further comprise a liquefied ethane branch line 20b.

The liquefied ethane branch line 20b is branched between the evaporative gas compressor 14 on the ethane cycle line 20a and the liquefaction device 17 and is supplied to the liquefaction device 17 on the ethane cycle line 20a and the liquefaction device 17 Liquefied gas heat exchanger (33), which is connected between the tanks (10).

At this time, a liquefied ethane branching valve (not shown) is provided in the liquefied ethane branch line 20b, and the supply amount of the ethane-evaporated gas or the liquefied ethane can be adjusted in accordance with the opening degree of the liquefied ethane branching valve.

The ethane-liquefied gas heat exchanger 33 exchanges heat between the ethane evaporated gas supplied from the ethane storage tank 10 and the liquefied gas supplied from the liquefied gas storage tank 30.

Specifically, the ethane-liquefied gas heat exchanger 33 is provided between the pump 31 and the liquefied gas heat exchanger 32 on the liquefied gas supply line 24 to heat-exchange the ethane-evaporated gas and the liquefied gas . Ethane is cooled by the liquefied gas by heat exchange between the ethane-evaporated gas and the liquefied gas, and the liquefied gas is heated by the ethane-evaporated gas to recover the ethane-evaporated gas from the cold heat of the liquefied gas, It can be recovered.

5, the ethane-liquefied gas heat exchanger 33 in the fifth embodiment of the present invention is directly connected to the ethane circulation line 20a to exchange heat between the ethane-evaporated gas and the liquefied gas, The gas may be precooled and supplied to the liquefaction device 17, and the liquefied gas may be preheated and supplied to the liquefied gas heat exchanger 32.

In this case, the ethane-liquefied gas heat exchanger 33 functions as a precooler for precooling the ethane-evaporated gas before re-liquefying of the refueling device 17 and for preheating the liquefied gas before vaporization of the liquefied gas heat exchanger 32 The role of the preheater can be performed at the same time.

6, in the modification of the fifth embodiment of the present invention, the ethane-liquefied gas heat exchanger 33 is provided on the liquefied ethane branch line 20b to heat-exchange the ethane-evaporated gas and the liquefied gas The ethane-evaporated gas may be re-liquefied and fed to the ethane storage tank 10, and the liquefied gas may be preheated and fed to the liquefied gas heat exchanger 32.

In this case, the ethane-liquefied gas heat exchanger 33 performs the role of re-liquefaction in the same manner as the re-liquefier of the liquefaction device 17, and performs the pre-liquefaction of the pre-vaporized liquefied gas in the liquefied gas heat exchanger 32 It is possible to perform the role of re-liquefaction and the pre-heater simultaneously.

Liquefied gas heat exchanger 33 in the modified example of the fifth embodiment is supplied with a larger amount of liquefied gas than the ethane-liquefied gas heat exchanger 33 in the fifth embodiment, .

The liquefied gas processing system 5b according to the modified example of the fifth embodiment of the present invention may further include a phase separator (not shown).

The phase separator is provided between the ethane-liquefied gas heat exchanger (33) and the ethane storage tank (10), separates the phases by supplying the resaturated ethane-evaporated gas from the ethane-liquefied gas heat exchanger (33) The ethane-evaporated gas is supplied to the ethane storage tank 10, and the ethane-evaporated gas that has not been re-liquefied can be returned to the re-liquefier 17.

In the liquefied gas processing systems 5a and 5b according to the modified examples of the fifth and fifth embodiments of the present invention, by providing the ethane-liquefied gas heat exchanger 33, the cold heat of the liquefied gas is recovered, And the heat of the liquefied gas heat exchanger (32) can be improved by the recovery of the heat of the liquefied gas heat exchanger (32) since the heat of the liquefied gas heat exchanger (32) There is an energy saving effect.

Further, the re-liquefaction efficiency of the re-liquefier 17 can be improved, and the size of the re-liquefaction cycle can be reduced, thereby making it possible to reduce the size of the re-liquefier 17.

Thus, the liquefied gas processing system 5a, 5b according to the present invention is equipped with a system for treating the marine floating structure with ethane or liquefied gas through the low-speed two-stroke low-pressure gas injection engine 111, The low-speed two-stroke low-pressure gas injection engine 111 has a small installation area and can enlarge the use space of the floating structure of the marine structure, and the configuration of the system The reliability of the driving is improved and the installation cost is saved.

The liquefied gas processing system 5a, 5b according to the present invention further includes an ethane-liquefied gas heat exchanger 33 to recover the cold heat of the liquefied gas, thereby pre-cooling the ethane-evaporated gas before liquefaction, Liquefaction can be performed, and the efficiency of re-liquefaction can be maximized.

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

1,2,3,4,5a, 5b: liquefied gas treatment system 10: ethane storage tank
11: Demand point 111: Low-speed two-stroke low-pressure injection engine
112: DFDE 12: fuel reforming device
13: Forced vaporizer 14: Evaporative gas compressor
141: evaporative gas first compressor 142: evaporative gas second compressor
15: phase separator 16: mixer
17: Re-liquefier device 171: Re-liquefied refrigerant device
20: vaporizing ethane feed line 20a: ethane circulating line
20b: liquefied ethane branch line 21: liquefied ethane feed line
22: liquefied ethane return line 23: vaporized ethane branch line
24: liquefied gas supply line 24a: liquefied gas branch line
241: Liquefied gas control valve 25: Liquefied refrigerant circulation line
251: Re-liquefied refrigerant return line 252: Re-liquefied refrigerant supply line
26: cold source circulation line 261: cold source supply line
262: cold source return line 30: liquefied gas storage tank
31: Pump 32: Liquefied gas heat exchanger
33: Ethane-liquefied gas heat exchanger

Claims (9)

An ethane storage tank for storing ethane;
A low-speed two-stroke low-pressure gas injection engine that receives the ethane from the ethane storage tank and supplies thrust to the floating structure of the sea;
An evaporative gas compressor for pressurizing the ethane-evaporated gas supplied from the ethane storage tank; And
And a fuel reforming device for increasing the methane value of the ethane-evaporated gas. The compressor according to claim 1,
An evaporating gas first compressor for pressurizing the vaporized ethane to a low pressure and supplying the pressurized gas to the fuel reformer; And
And an evaporative gas second compressor which pressurizes the reformed ethane vapor to a pressure required by the low-pressure two-stroke low-pressure gas injection engine and supplies the pressurized gas to the low-speed two-stroke low-pressure gas injection engine. 3. The method of claim 2,
DFDE < / RTI >
The fuel reforming apparatus includes:
And supplies the reformed ethane-evaporated gas to the DFDE or supplies the reformed-gas-evaporated gas to the evaporated-gas second compressor. The method according to claim 1,
A forced vaporizer for forcibly vaporizing the ethane stored in the ethane storage tank; And
Further comprising a phase separator for separating the phase of vaporized ethane supplied from said forced vaporizer. 5. The method of claim 4,
DFDE;
A vaporized ethane feed line connecting the ethane storage tank and the slow two stroke low pressure gas injection engine and including the phase separator, the evaporative gas compressor, and the fuel reformer;
A liquefied ethane feed line connecting the ethane storage tank and the phase separator and having the forced vaporizer;
A liquefied ethane return line connecting the phase separator and the ethane storage tank to return the liquid separated ethane to the ethane storage tank; And
Further comprising a vaporized ethane branch line connecting the reformer and the DFDE to feed the reformed ethane to the DFDE. 6. The fuel reforming apparatus according to claim 5,
To supply the reformed ethane vapor to the DFDE, or to supply the reformed ethane vapor to the low-pressure two-stroke low-pressure gas injection engine. The method of claim 1, wherein the ethane storage tank comprises:
Wherein the liquefied gas is an independent tank. The evaporative-gas first compressor according to claim 2,
Pressurized to a low pressure of 5 to 10 bar,
The evaporative gas second compressor includes:
Lt; RTI ID = 0.0 > 12 < / RTI > bar to 20 bar. The fuel reforming apparatus according to claim 1,
Characterized in that the methane gas is reformed into MN80 to MN90.

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