KR20190081314A - System and Method for Liquefied Gas Regasification System with Organic Rankine Cycle - Google Patents

Abstract

The present invention relates to a regasification system for liquefied gas and a method for the same and, more specifically, to a regasification system for liquefied gas, using an organic Rankine cycle, and a method for the same. The regasification system for liquefied gas, using the organic Rankine cycle, is used to produce electric power by supplying cold and heat obtained while the liquefied gas is gasified to the organic Rankine cycle. The regasification system for liquefied gas also uses thermal energy obtained from the organic Rankine cycle for power production to gasify the liquefied gas. Moreover, the regasification system for liquefied gas can improve regasification efficiency and reliquefaction efficiency by liquefying evaporation gas using the cold and heat of the liquefied gas. According to the present invention, the regasification system for liquefied gas includes: a reliquefaction unit reliquefying the evaporation gas generated as the liquefied gas is naturally gasified, and collecting the reliquefied evaporation gas; a regasification unit gasifying the liquefied gas and supplying the liquefied gas to a place demanding the regasified gas; and a thermal medium circulation unit supplying a thermal medium to the regasification unit and producing electric power by collecting the thermal medium collecting the heat and cold from the liquefied gas in the regasification unit. The regasification unit includes: a compressor compressing the evaporation gas; and a heat collecting device collecting the cold and heat of the evaporation gas before the compression and cooling the compressed evaporation gas and the thermal medium collected to the thermal medium circulation unit.

Description

Technical Field [0001] The present invention relates to a system and a method for regenerating a liquefied gas using an organic Rankine cycle,

The present invention relates to a liquefied gas regeneration system and method, and more particularly, to a liquefied gas regeneration system and a liquefied gas recycling system, The present invention relates to a liquefied gas regeneration system and method using an organic Rankine cycle capable of improving regeneration efficiency and re-liquefaction efficiency by liquefying evaporation gas using cold heat of a liquefied gas.

Generally, natural gas is liquefied at the place of production, stored in the state of LNG (Liquefied Natural Gas) and transported to the destination by LNG carrier. LNG is obtained by cooling the natural gas to a cryogenic temperature of about -163 ° C at normal pressure. LNG is very suitable for long haul because its volume is reduced to about 1/600 compared to that of natural gas. The LNG transported to the destination is unloaded to the offshore or offshore gas terminal, regasified using the regasification system, and the regas gas is supplied to the gas consumer through the regas network.

The LNG regasification system includes a vaporizer that vaporizes the LNG by heat exchange. As the heat source for vaporizing the LNG in the vaporizer, a heat source obtained from nature such as seawater or atmosphere may be used, or waste heat or electricity may be used.

Since the LNG is mainly transported by sea by the ship and the re-gasification system is installed on the floating ship or the offshore terminal on the shore, the vaporizer of the re-gasification system mainly uses seawater as a heat source to vaporize the LNG.

In a vaporizer of a LNG regasification system using seawater as a heat source, LNG is vaporized and the seawater is cooled by heat exchange between seawater and LNG. The cooled seawater is vented to the sea while vaporizing the LNG.

However, if the cooled seawater is discharged into the sea while vaporizing the cryogenic LNG, environmental pollution due to the change in the surrounding sea temperature may be caused.

On the other hand, while vaporizing LNG, seawater can often occur by icing of LNG. In addition, when the temperature of the seawater is low, such as in the winter or polar regions, it does not provide sufficient heat to vaporize the LNG, thereby significantly reducing the heat exchange efficiency.

In recent years, an indirect regasification system for vaporizing LNG while circulating a separate heating medium such as glycol water has been spotlighted, in order to solve such a problem, not by direct heat exchange with seawater and LNG.

However, even in the case of applying the indirect heat exchange type regeneration system, it is necessary to reheat the cooled heat medium while vaporizing the LNG in the vaporizer. For example, additional boilers are used to produce steam, steam is used to reheat the heat medium, or a large-capacity heat exchanger is installed to heat the seawater and the heat medium, and reheating the heat medium using seawater. The configuration of the system becomes complicated.

Further, in both the direct heat exchange system and the indirect heat exchange system, the cold heat obtained while vaporizing the LNG, for example, the heat medium having a lower temperature discharged from the vaporizer or the condensed steam while heating the lower heat medium, heat sink, or sea.

Accordingly, it is an object of the present invention to solve the above-mentioned problems, and it is an object of the present invention to provide an indirect heat exchange type regeneration system capable of improving regeneration efficiency and performance, Lt; RTI ID = 0.0 > liquefied gas < / RTI > regeneration system.

According to an aspect of the present invention, there is provided an apparatus for regenerating liquefied gas, And a heating medium circulation unit for supplying a heating medium for vaporizing the liquefied gas to the regeneration unit, wherein the heating medium circulation unit comprises: a power generation unit for generating electric power by using the recovered cooling heat while vaporizing the liquefied gas; And a liquefied gas regeneration system using an organic Rankine cycle in which the heat medium is heated using the heat of condensation recovered while generating power in the power generation section and supplied to the regeneration section.

Preferably, the regeneration unit includes a vaporizer for vaporizing the liquefied gas by heat exchange with the heating medium; And a trim heater that heats the regasification gas by heat exchange with the heating medium when the regasification gas vaporized in the vaporizer is lower than a temperature required by the gas consumer.

Preferably, the power generation section includes a working fluid pump that pressurizes and circulates the working fluid; A working fluid evaporator for heating the working fluid with a superheated gas; A turbine generator for generating electric power by driving the turbine with the superheated gas; And a working fluid condenser for condensing the working fluid discharged from the turbine generator into a saturated liquid state using cold heat recovered while vaporizing the liquefied gas, wherein the working fluid pump sucks the working fluid in the saturated liquid state can do.

Preferably, the liquefied gas regeneration system further includes an evaporation gas processing unit for processing the evaporation gas generated from the liquefied gas storage tank storing the liquefied gas, and the evaporation gas processing unit is operable to convert the evaporation gas into a low pressure And a low-pressure compressor for compressing the gas at a low pressure required by the gas consumer.

Preferably, the evaporation gas processing unit may further include a suction drum for condensing the low-pressure evaporated gas compressed by the low-pressure compressor to the cold heat of the liquefied gas to be supplied to the vaporizer.

Preferably, the regeneration unit further comprises a high-pressure pump for compressing the liquefied gas discharged from the suction drum to a pressure required by the customer for reclaimed gas, wherein the liquefied gas compressed at a high pressure in the high- .

Preferably, the evaporation gas processing unit may further include a high-pressure compressor for compressing the evaporation gas to a high pressure required by the re-used gas consumer.

Preferably, the apparatus further comprises a first temperature measuring unit for recovering the cold heat of the liquefied gas in the regeneration unit and measuring the temperature of the heat medium recovered in the heat medium circulation unit, and bypasses the regeneration unit from the heat medium circulation unit, A first flow control valve for regulating the flow rate of the liquefied gas to be recycled to the circulation portion; And a load controller for controlling the first flow rate control valve according to a measured value of the first temperature measurement unit and a power generation load of the power generation unit.

Preferably, the second temperature measuring unit measures the temperature of the working fluid supplied to the turbine generator. A first flow control valve for bypassing the regeneration portion from the heat medium circulation portion and regulating a flow rate of the liquefied gas to be recirculated to the heat medium circulation portion; A fifth flow control valve for controlling the temperature of the heat source for heating the working fluid in the working fluid evaporator; And a load controller for controlling the fifth flow rate control valve according to a measured value of the second temperature measurement unit and a power generation load of the power generation unit.

According to another aspect of the present invention, there is provided a vaporizer for vaporizing a liquefied gas by exchanging heat between a liquefied gas and a heat medium in a vaporizer, recovering the cooled heat medium to a heat medium circulation section while vaporizing the liquefied gas, A method of regenerating a liquefied gas using an organic Rankine cycle is provided, wherein the working fluid is condensed, the heating medium is heated, the heated heating medium is circulated to the vaporizer, and the working fluid is circulated to produce electric power.

Preferably, if the regasification gas vaporized in the vaporizer is lower than the temperature required by the regasification gas consumer, the regasification gas can be heated by heat-exchanging the heated heat medium and the regasification gas.

Preferably, the temperature of the heat medium recovered by the heat medium recovery unit is measured, and the heat medium recovered by the heat medium recovery unit without heat exchange with the liquefied gas or the regeneration gas according to the measured temperature of the heat medium and the power production load Can be controlled.

Preferably, the evaporation gas produced by natural vaporization of the liquefied gas is compressed to a pressure required by the consumer of the low-pressure gas, and before the liquefied gas to be regasified is supplied to the vaporizer, After condensation, it can be vaporized.

Preferably, when the flow rate of the liquefied gas is insufficient to condense the evaporated gas, at least a part of the evaporated gas may be compressed to a high pressure required by the reclaimed gas consumer and supplied to the reclaimed gas consumer.

Preferably, the heat medium circulation unit pressurizes the working fluid, evaporates the working fluid into a superheated gas state, drives the turbine with the superheated gas to produce electric power, drives the turbine, A cycle for recovering the cold heat of the liquefied gas and condensing the heat medium by heat exchange with the heat medium recovered to the heat medium circulation unit can be formed.

According to another aspect of the present invention, there is provided a re-liquidation unit for re-liquefying and recovering evaporated gas generated by spontaneous vaporization of liquefied gas; A regeneration unit for vaporizing the liquefied gas and supplying the vaporized liquefied gas to a demand site for regasification gas; And a heat medium circulation unit for supplying a heating medium to the regeneration unit and recovering a heat medium recovered from the liquefied gas from the liquefied gas in the regeneration unit to produce electric power, wherein the re-liquefaction unit comprises: a compressor for compressing the evaporation gas; And a heat recovery device for recovering the cold heat of the pre-compression evaporation gas to cool the compression evaporation gas and the heat medium recovered to the heat medium circulation part.

Preferably, the regeneration unit includes a high-pressure pump for compressing the liquefied gas to be vaporized; A preheater for recovering the cold heat of the compressed liquefied gas and cooling the compressed evaporative gas cooled in the heat recovery unit; And a vaporizer for vaporizing the compressed liquefied gas recovered from the preheater by heat exchange with the heat medium.

Preferably, the heat medium circulation part includes a power generation part in which the working fluid circulates, and the power generation part includes: a working fluid condenser for supplying the working fluid to the cold heat recovered by the heating medium; A working fluid evaporator for generating a working fluid condensed in the evaporating gas condenser as a superheated gas; And a turbine generator for driving the turbine with the superheated gas and generating electric power, wherein the coolant of the recovered heat medium is recovered as the working fluid in the working fluid condenser, and the heat medium heated by the condensation heat of the working fluid And a heating medium supply pump for supplying the regenerating unit to the regeneration unit.

Preferably, the third flow control valve controls the flow path of the compressed evaporative gas so that the compressed evaporative gas bypasses the heat recovery device and joins to the downstream end of the heat recovery device. And a load controller for controlling the temperature of the heat medium recovered to the power generator by controlling the third flow rate control valve according to a power generation load of the turbine generator.

Preferably, the re-liquefaction section includes: an expansion valve that reduces the pressure of the compressed evaporative gas while passing through at least one of the heat recovery apparatus and the pre-heater; And a gas-liquid separator for separating the decompressed evaporative gas passed through the expansion valve by gas-liquid separator, wherein the liquid-state re-liquefied vapor gas separated from the gas-liquid separator can be recovered to the liquefied gas storage tank.

Preferably, the fourth evaporation gas branch line joins the gaseous re-liquefied gaseous vapor separated in the gas-liquid separator to the vaporized gas stream supplied to the heat recovery unit, The flow rate of the evaporative gas flowing through the fourth evaporative gas branch line can be regulated.

The apparatus may further include a trim heater that heats the regasification gas by heat exchange with the heating medium when the regasification gas vaporized in the vaporizer is lower than a temperature required by the gas consumer.

Preferably, the first flow control valve controls the flow path of the heating medium supplied to the regeneration unit and the flow path of the heating medium that bypasses the regeneration unit and is returned to the heating medium circulation unit. And a load controller for controlling the temperature of the heat medium to be returned to the heat medium circulation unit by controlling the first flow rate control valve according to a power generation load of the turbine generator.

Preferably, the evaporation gas produced in the high-pressure pump is joined to the evaporative gas stream supplied to the heat recovery unit, or the sixth evaporative gas branch Line; < / RTI >

According to still another aspect of the present invention, there is provided a method for producing a liquefied natural gas by vaporizing a liquefied gas by heat exchange with a heating medium, The heating medium is recovered by recovering the cold heat to generate electric power, and the heating medium is recovered by heating the heated heating medium. The heating medium is circulated through the heating medium circulation unit, There is provided a liquefied gas regeneration method using an organic Rankine cycle in which the liquefied gas is circulated to regenerate the liquefied gas.

Preferably, the evaporation gas is compressed, the cold heat of the pre-compression evaporation gas is recovered, and the compression evaporation gas and the heat medium recovered to the heat medium circulation unit can be cooled.

Preferably, the flow rate of the compressed evaporation gas to be heat-exchanged with the pre-compression evaporation gas is controlled according to the power production load, and the temperature of the heat medium to be returned to the heat medium circulation unit according to the flow rate regulation of the pre- .

Preferably, when the temperature of the regeneration gas vaporized by the heat exchange with the heat medium is lower than the temperature required by the regeneration gas consumer, the heat can be heated by heat exchange with the heat medium.

Preferably, the flow rate of the heat medium to be vaporized by the liquefied gas, the flow rate of the heat medium to be heated by the regeneration gas, and the flow rate of the heat medium to be circulated to the heat medium circulation section without heat exchange with the liquefied gas or regeneration gas, The temperature of the heat medium to be returned to the heat medium circulation unit can be adjusted by controlling the flow rate.

Preferably, the liquefied gas to be vaporized is compressed, the compressed liquefied gas is preheated by heat exchange with compressed evaporation gas cooled by heat exchange with the pre-compression evaporation gas, and then the preheated compressed liquefied gas is introduced into the heat medium The vaporization can be performed by heat exchange of the gas.

According to the present invention, it is possible to improve the regeneration efficiency and performance of the indirect heat exchange regeneration system, and also to recycle the obtained cold heat while vaporizing the liquefied gas.

In particular, the energy efficiency of the liquefied gas regeneration system is improved because the organic Rankine cycle is applied to produce power by utilizing the cold heat obtained while vaporizing the liquefied gas.

In addition, thermal energy for regenerating the liquefied gas can be obtained from the organic Rankine cycle, so that the liquefied gas can be effectively regenerated without causing problems such as environmental pollution and deterioration of heat exchange efficiency due to freezing of seawater.

It is also possible to integrate the heat source supply system in the regasification system by using a heat source for regenerating the liquefied gas without separately providing a heat source for heating the regasification gas to a temperature required by the gas consumer, .

In addition, the system operation cost can be reduced accordingly, which is economical.

Further, since the evaporated gas generated in the liquefied gas regeneration system can be re-liquefied and recovered again, it is possible to prevent the liquefied gas from being wasted and to prevent the pressure of the liquefied gas storage tank from rising excessively.

1 is a schematic view showing an LNG regeneration system according to a first embodiment of the present invention.
2 is a schematic view illustrating an LNG regeneration system according to a second embodiment of the present invention.

In order to fully understand the operational advantages of the present invention and the objects attained by the practice of the present invention, reference should be made to the accompanying drawings, which illustrate preferred embodiments of the present invention, and to the contents of the accompanying drawings.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, like reference numerals refer to like elements throughout. The same elements are denoted by the same reference numerals even though they are shown in different drawings. In addition, the following examples can be modified in various forms, and the scope of the present invention is not limited to the following examples.

The liquefied gas may be a liquefied natural gas (LNG), a liquefied ethane gas (LEG), or a liquefied petroleum gas (LPG) Gas, liquefied ethylene gas, liquefied propylene gas, and the like. Alternatively, it may be a liquid gas such as liquefied carbon dioxide, liquefied hydrogen, or liquefied ammonia. However, in the following embodiments, LNG, which is a typical liquefied gas, is applied will be described as an example.

LNG is mainly composed of methane, and includes ethane, propane, butane, etc., and its composition may vary depending on the place of production.

Also, the LNG regeneration system according to an embodiment of the present invention described below is applied to a ship as an example, but may also be applied on the land.

Also, in one embodiment of the present invention, the LNG regasification vessel may be any type of ship equipped with an LNG regeneration facility capable of regenerating LNG and supplying it to a gas demanding place, that is, an LNG RV (Regasification Vessel) And floating structures that do not have propelling capabilities, such as floating storage regasification units (LNG FSRUs), but float at sea. However, in the following embodiments, the LNG FSRU will be described as an example.

Also, the LNG regasification vessel according to an embodiment of the present invention is characterized in that the LNG is regasified at sea and the regasification gas is supplied to the demand side of the gas on the land via the pipeline network.

FIG. 1 is a schematic view showing an LNG regeneration system according to a first embodiment of the present invention, and FIG. 2 is a schematic view illustrating an LNG regeneration system according to a second embodiment of the present invention. Hereinafter, an LNG regeneration system and method using an organic Rankine cycle according to one embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG.

First, referring to FIG. 1, a system and method for regenerating LNG using an organic Rankine cycle according to a first embodiment of the present invention will be described.

The LNG regeneration system according to the first embodiment of the present invention includes an LNG storage tank 100 for storing LNG; A regeneration unit for regenerating the LNG stored in the LNG storage tank 100 and supplying the LNG to the gas consumer; An evaporation gas processing unit for processing the evaporation gas generated by natural vaporization of LNG in the LNG storage tank 100; And a heat medium circulation unit for circulating the heat medium for regenerating the LNG. The LNG storage tank 100, the regeneration unit, the evaporation gas treatment unit, and the heat medium circulation unit of the present embodiment are connected to each other organically and operated organically.

It is preferable that the LNG storage tank 100 of the present embodiment is heat-treated so that the LNG can be stored while being maintained in a liquid state. In this embodiment, the LNG may be stored in the LNG storage tank 100 at about 1.1 bar to about -163 캜.

Although FIG. 1 illustrates only one LNG storage tank 100, at least one LNG storage tank 100 of the present embodiment may be provided.

Also, even if the LNG storage tank 100 is adiabatically treated, the LNG can be spontaneously vaporized by external heat penetration in the LNG storage tank 100 to generate boil-off gas (BOG). Therefore, the LNG storage tank 100 may be designed to withstand a pressure rise caused by the evaporation gas generated in the LNG storage tank 100 to a set pressure. When the internal pressure of the storage tank exceeds the set pressure, And may be designed to discharge the vaporized gas in the LNG storage tank 100 to the outside of the LNG storage tank 100. [ The evaporated gas discharged from the LNG storage tank 100 is processed in the evaporative gas processing section of this embodiment.

The LNG storage tank 100 of the present embodiment may be provided with an LNG supply pump (not shown) for transferring the LNG from the LNG storage tank 100 to the regeneration unit. The LNG supply pump may be a semi-submerged pump installed inside the LNG storage tank, or may be installed outside the LNG storage tank.

The regeneration unit of this embodiment includes a high-pressure pump 120a for regenerating the LNG to be supplied to the gas consumer and supplying the compressed LNG to the vaporizer 140; And a vaporizer 140 for exchanging heat between the compressed LNG compressed by the high-pressure pump 120a and the heat medium supplied from the heat medium circulation unit, thereby vaporizing the compressed LNG.

The LNG storage tank 100, the regeneration unit, and the gas demanding unit of the present embodiment are connected by a regeneration line (LL). The LNG is discharged from the LNG storage tank 100 by the LNG supply pump, regenerated while flowing along the regeneration line LL, and supplied to the gas consumer.

In addition, the regeneration unit of the present embodiment temporarily stores the LNG discharged from the LNG supply pump before being supplied to the high-pressure pump 120a, and is maintained such that the high-pressure pump 120a can be smoothly operated And a suction drum (110).

That is, the LNG stored in the LNG storage tank 100 is sucked by the LNG supply pump and supplied to the suction drum 110, stabilized in the suction drum 110, and transferred to the high pressure pump 120a.

The suction drum 110 may be connected to the evaporation gas processing unit and may serve as a recondenser for transferring the evaporation gas and re-condensing the evaporation gas using the cooling heat of the LNG stored in the suction drum 110. The evaporated gas recycled in the suction drum 110 is supplied to the high-pressure pump 120a together with the LNG, regenerated in the vaporizer 140, and transferred to the gas consumer.

In this embodiment, the 'LNG to be regasified' supplied to the high-pressure pump 120a can be interpreted as a concept including condensed evaporative gas in a liquid state condensed in the suction drum 110.

The high-pressure pump 120a of this embodiment compresses the LNG to be regenerated, which is transferred from the suction drum 110, to a high pressure. Here, the high pressure is a pressure higher than the critical pressure of the LNG, and may be a pressure required by the gas consumer. For example, the high pressure pump 120a of this embodiment can compress the LNG to about 100 barg or more.

The heat exchange efficiency in the vaporizer 140 can be increased by compressing the LNG to be vaporized in this embodiment to a pressure higher than the critical pressure of the LNG. That is, the LNG compressed by the high-pressure pump 120a and transferred to the vaporizer 140 may be in a supercritical state.

The carburetor 140 of the present embodiment vaporizes LNG compressed at a high pressure in the high-pressure pump 120a by heat exchange with the heating medium.

In this embodiment, the heating medium is a glycol water transferred from a heating medium circulation section described later, and the compressed LNG is a high-pressure LNG compressed at about 100 barg or more in the high-pressure pump 120a. The high pressure LNG is vaporized by heat exchange in the vaporizer 140 and transferred to the high pressure gas consumer, and the glycol water obtains cold heat from the high pressure LNG while vaporizing the high pressure LNG. The glycol water that has been cooled and obtained from the high-pressure LNG is fed back to the heat medium circulation section.

In this embodiment, the high-pressure gas consumer may be a regasification gas terminal installed on the land.

As described above, the high-pressure LNG transferred from the high-pressure pump 120a to the vaporizer 140 may be supercritical. Thus, in the present specification, "vaporizing" means not only a phase change from a liquid phase to a gaseous phase but also a phenomenon in which heat energy is transferred from a heat medium to an LNG, that is, LNG receives thermal energy from a heat medium, .

The regeneration unit of the present embodiment may further include a trim heater 150 for regulating the temperature of the regeneration gas vaporized in the vaporizer 140 and transferred to the high-pressure gas consumer, to a temperature required by the high-pressure gas consumer.

The trim heater 150 according to the present embodiment heats the regeneration gas vaporized in the vaporizer 140 to about 20 占 폚 or more, or the room temperature.

In addition, the trim heater 150 is connected to the heating medium circulation unit, and the heating medium for heating the regeneration gas in the trim heater 150 may be a heating medium supplied from the heating medium circulation unit, in this embodiment, glycol water.

The LNG stored in the LNG storage tank 100 of the present embodiment is supplied to the suction drum 110 by the LNG supply pump and is compressed by the high pressure pump 120a to a pressure required by the high pressure gas consumer, And the temperature is controlled by the trim heater 150, and is transferred to the high-pressure gas consumer.

The LNG storage tank 100, the suction drum 110, the high pressure pump 120a, the vaporizer 140, the trim heater 150 and the high-pressure gas consumer in the present embodiment are connected by the regeneration line LL, Is regenerated and transported from the LNG storage tank 100 to the high-pressure gas consumer along the regasification line LL.

The evaporation gas processing section of the present embodiment includes an evaporation gas compressor for compressing the evaporation gas and supplying it to the gas consumer.

The evaporative gas compressor includes a low-pressure compressor (210) for compressing the evaporated gas to a pressure required by the consumer of the low-pressure gas; And a high-pressure compressor (220) for compressing the evaporated gas to a pressure required by the high-pressure gas consumer.

In this embodiment, the low-pressure gas consumer may be a gas consumer in-ship or a gas consumer on-board or off-shore. For example, the low pressure gas consumer may be a low pressure gas injection engine requiring a low pressure gas of about 2 bar to 8 bar, such as an inboard DFDE engine.

In addition, in this embodiment, the high-pressure gas consumer can be a gas consumer in-ship or a off-shore or terrestrial gas consumer. For example, the high pressure gas consumer may be a high pressure gas injection engine requiring a high pressure gas of about 150 bar to 300 bar, such as onshore gas terminals, ME-GI engines onboard. In this embodiment, it is assumed that the high-pressure gas consumer is an onshore gas terminal requiring a high-pressure regeneration gas of about 100 barg or more.

The high-pressure compressor 220 of this embodiment may not be installed as required. When the high-pressure compressor 220 and the low-pressure compressor 210 are installed together, the low-pressure compressor 210 may compress the evaporation gas to a pressure required by the low-pressure gas compressor, compress the evaporation gas to a low pressure And may be supplied to the high-pressure compressor 220.

1, the high-pressure compressor 220 is installed at the rear end of the low-pressure compressor 210 as an example. However, the present invention is not limited thereto, and the high-pressure compressor 220 and the low-pressure compressor 210 may be installed in parallel. In the present embodiment, as shown in FIG. 1, a description will be made by taking as an example that the low-pressure compressor 210 and the high-pressure compressor 220 are connected in series. In this embodiment, The low-pressure evaporation gas may be branched and supplied to at least one of the suction drum 110, the low-pressure gas consumer, and the high-pressure compressor 220.

The LNG storage tank 100, the evaporation gas processing unit, the low-pressure gas consumer, and the high-pressure gas consumer in the present embodiment can be connected by the evaporation gas line BL.

The evaporation gas line (BL) includes a plurality of branch lines branched at the downstream end of the low-pressure compressor (210). 1, a plurality of evaporative gas branch lines are branched at the rear end of the low-pressure compressor 210. However, the present invention is not limited thereto. A plurality of evaporative gas branch lines may be branched at a rear end of the LNG storage tank 100 and a front end of the low pressure compressor 210 and a low pressure compressor 210 may be selectively installed at each branch line. However, in the present embodiment, as shown in FIG. 1, all of the evaporated gas discharged from the LNG storage tank 100 is compressed at a low pressure by the low-pressure compressor 210 and then branched.

The evaporation gas line BL of this embodiment includes a first evaporation gas line BL1 that connects the low pressure compressor 210 and the suction drum 110 and allows the low pressure evaporation gas to be transferred to the suction drum 110; A second evaporation gas branch line BL2 connecting the low pressure compressor 210 and the high pressure compressor 220 and allowing the evaporated gas compressed at a high pressure to be transferred to a high pressure gas consumer; And a third evaporative gas branch line (BL3) for connecting the low-pressure compressor (210) to the low-pressure gas consumer and delivering the low-pressure evaporated gas to the low-pressure gas consumer.

The high-pressure gas consumer of the present embodiment may be a land gas terminal supplied with the regeneration gas described above.

Further, the low-pressure gas consumer may be an engine installed in the ship. The engine can use natural gas compressed to about 2 bar to 8 bar, about 6.5 bar as fuel. In this embodiment, the low pressure compressor can compress the evaporation gas to about 2 bar to 8 bar, to about 6.5 bar.

The suction drum 110 is connected to the evaporation gas line BL and the regasification line LL, as shown in Fig. In the suction drum 110, the low-pressure evaporation gas transferred along the evaporation gas line BL and the LNG transferred from the LNG storage tank 100 along the regasification line LL are mixed with each other, The evaporation gas is condensed.

The condensed vaporized gas recycled by the cooling of LNG and LNG transferred from the suction drum 110, that is, the LNG transferred from the LNG storage tank 100 to the suction drum 150 along the regasification line LL, Pressure pump 120a.

Therefore, according to the present embodiment, the evaporation gas discharged from the LNG storage tank 100 can be compressed and supplied to at least one of the low-pressure gas consumer, the high-pressure gas consumer, and the suction drum 110.

The heating medium circulating unit of this embodiment includes a heating medium line GL connecting the heating medium circulating unit and the regrounding unit; A heating medium circulation pump 310 for pressurizing the heating medium such that the heating medium flows along the heating medium line GL; And a power generation unit for recovering cold and heat of the heat medium which has been cooled by the heat exchange in the regeneration unit.

In the present embodiment, the heating medium flows along the heating medium line GL, recovers the cold heat of the LNG while exchanging heat with the LNG in the regeneration section, and the cooling medium, which is cooled by heat exchange with the LNG, The heating medium whose temperature has risen is pressurized by the heat medium circulation pump 310 and supplied to the regeneration unit.

In this embodiment, the heating medium is exemplified by glycol water.

The heat medium circulation part of the present embodiment is provided between the power generation part and the heat medium circulation pump 310 and accommodates the heat medium discharged from the power generation part to heat the heat medium supplied from the power generation part to the heat medium circulation pump 310, And an expansion vessel (340) for holding the expansion vessel (340).

According to this embodiment, since the expansion valve 340 is provided to serve as a buffer for relieving the volume change of the glycol water supplied from the power generation portion to the heat medium circulation pump 310, the heat medium circulation pump 310 So that the cavitation phenomenon of the suction side of the heat medium circulation pump 310 can be prevented.

The heating medium circulating through the heating medium line GL by the heating medium circulation pump 310 can be used as a heat source for the vaporizer 140 and the trim heater 150 of the regeneration unit.

That is, the heating medium of this embodiment is supplied to the vaporizer 140 along the heating medium line GL, and is circulated to the power generation portion by receiving cold heat while vaporizing the LNG in the vaporizer 140.

The heating medium line GL of the present embodiment includes a first heating medium branch line GL1 branched from the heating medium line GL and connected to the trim heater 150. [ The heating medium of this embodiment is supplied to the trim heater 150 along the first heating medium branch line GL1 and is cooled by the trim heater 150 while vaporizing the LNG to circulate to the power generation section.

The heating medium line GL of the present embodiment may include a second heating medium branch line GL2 branched from the heating medium line GL and connected so that the heating medium bypasses the regeneration portion and is returned to the heating medium circulation portion.

At the point where the second heating medium branch line GL2 branches from the heating medium line GL, the flow rate of the heating medium supplied to the vaporizer 140, the flow rate of the heating medium supplied to the trim heater 150, And a first flow control valve 320 for controlling the flow rate of the heating medium branched to the line GL2.

The load controller 500, which will be described later, controls the amount of opening of the first flow control valve 320 in accordance with the temperature measurement value of the heating medium recovered to the power generation unit and the load of the power generation unit, have.

The temperature of the heating medium flowing along the heating medium line GL is measured in the heating medium line GL through which the heating medium is recovered from the regeneration section to the heating medium circulation section and the first temperature And a measurement unit TT1.

In this embodiment, the temperature of the heat medium supplied from the heat medium circulation part to the regeneration part may be about 40 占 폚.

The power generation portion of the present embodiment is an example of an organic Rankine Cycle in which electric power is generated using heat recovered by heat exchange with the LNG by the heat medium and recovery of the heat recovered by the heat medium is performed to heat the heat medium again. have.

The power generating portion of this embodiment includes a working fluid pump 410 for circulating the working fluid of the organic Rankine cycle; A working fluid evaporator (420) for evaporating the working fluid; A turbine generator 430 including a turbine driven using a working fluid evaporated in the working fluid evaporator 420 and a generator converting the driving force of the turbine into electric energy; And a working fluid condenser 440 for condensing the working fluid expanded while passing through the turbine generator 430 by using cold heat of the heat medium recovered from the LNG in the regeneration portion.

The working fluid of this embodiment may be, for example, a hydrocarbon-based single fluid such as ethane, propane, or a mixed fluid therebetween.

The working fluid pump 410, the working fluid evaporator 420, the turbine generator 430, and the working fluid condenser 440 of this embodiment are connected by a working fluid line WL through which the working fluid flows.

Further, the working fluid condenser 440 is also connected to the heating medium line GL. That is, in the working fluid condenser 440, the working fluid and the heating medium exchange heat, the working fluid condenses, and the heating medium is heated. The working fluid condensed in the working fluid condenser 440 is circulated to the working fluid pump 410 along the working fluid line WL and the heated fluid in the working fluid condenser 440 is circulated through the heating medium circulation line GL And is circulated to the pump 310.

The working fluid evaporator 420 is connected to a working fluid line (WL) through which the working fluid flows and a cycle heating medium line (HL) through which the working fluid circulates by heat exchange with the working fluid to evaporate the working fluid. That is, in the working fluid evaporator 420, the working fluid and the cycle heating medium exchange heat, the working fluid evaporates, and the cycle heating medium is cooled.

The working fluid line WL is provided with a second temperature measuring unit TT2 for measuring the temperature of the working fluid supplied from the working fluid evaporator 420 to the turbine generator 430 and for transmitting the measured temperature value to the load controller 600 ) May be provided.

A fifth flow control valve 510 is provided in the cycle heating medium line HL to regulate the flow rate of the cycle heating medium supplied from the unillustrated cycle heating medium supply unit to the working fluid evaporator 420.

The load controller 600 adjusts the amount of opening of the fifth flow control valve 510 according to the measured value of the second temperature measurement unit TT2 and the power generation load of the turbine generator 430. [ The flow rate of the cycle heating medium supplied to the working fluid evaporator 420, that is, the temperature of the working fluid superheated gas formed in the working fluid evaporator 420, is controlled by adjusting the amount of opening of the fifth flow control valve 510. That is, the load controller 600 controls the working fluid to be supplied to the turbine generator 430 at a temperature suitable for the power load to be produced by the turbine generator 430.

The cycle heating medium line HL of the present embodiment may further include a first cycle heating medium branch line HL1 that branches from the cycle heating medium line HL and is formed such that the cycle heating medium bypasses the working fluid evaporator 420 .

A fifth flow control valve 510 may be installed at a point where the first cycle heating medium branch line HL1 is branched from the cycle heating medium line HL.

A part of the cycle heating medium supplied from the cycle heating medium supply section to the working fluid evaporator 420 under the control of the fifth flow control valve 510 is supplied to the working fluid evaporator 420 along the first cycle heating medium branch line HL1 It can be bypassed and recycled to the cycle heating medium supply section.

The working fluid superheated gas becomes a low pressure saturated liquid while the turbine generator 430 drives the turbine, and a working fluid in a low pressure saturated liquid state is supplied to the working fluid condenser 440.

The LNG regeneration system according to the present embodiment controls the first flow rate control valve 320 and the fifth flow rate control valve 510 to control the flow rate of the gas (600) for controlling the temperature of the flowing heat medium, the temperature of the working fluid flowing along the working fluid line (WL) and the temperature of the cycle heating medium flowing along the cycle heating medium line (HL) .

Hereinafter, the operation principle of the LNG regeneration system according to the first embodiment of the present invention will be described.

The LNG to be regasified is supplied from the LNG storage tank 100 to the high pressure pump 120a by operating the LNG supply pump. At this time, the LNG discharged from the LNG supply pump is supplied to the suction drum 110 before being supplied to the high-pressure pump 120a.

The flow rate of the LNG supplied from the suction drum 110 to the high-pressure pump 120a can be controlled according to the regeneration gas flow rate required by the high-pressure gas consumer. Further, the level and the internal pressure of the suction drum 110 are kept constant. The level and the internal pressure of the suction drum 110 control the operation state of the LNG supply pump and the high pressure pump 120a and the flow rate of the evaporation gas supplied to the suction drum 110 through the first evaporation gas branch line BL1 .

The evaporated gas generated in the LNG storage tank 100 is compressed to a low pressure and supplied to a low-pressure gas consumer such as an on-board engine. Part of the remaining low-pressure evaporated gas supplied to the low- And supplies it to the suction drum 110. In the suction drum 110, the low-pressure evaporation gas is condensed into a liquid state by the cold heat of the LNG to be regenerated, which is stored while maintaining a certain level in the suction drum 110.

The flow rate of the low-pressure evaporation gas supplied to the suction drum 110 through the first evaporation gas branch line BL1 is determined by the flow rate of the evaporation gas discharged from the LNG storage tank 100, The flow rate, the flow rate of the LNG to be regasified, the level of the suction drum 110, and the internal pressure.

For example, when the regeneration is not performed or the flow rate of the LNG to be regasified is not sufficient to condense the low-pressure evaporation gas in the suction drum 110, the low-pressure gas supplied to the first evaporation gas branch line BL1 The low-pressure evaporation gas branched to the first evaporation gas branch line BL1 is branched to the second evaporation gas branch line BL2, the high-pressure compressor 220 compresses the high-pressure gas, It is supplied to the customer and processed.

The high pressure pump 120a is used to compress the LNG introduced from the suction drum 100 to a pressure required by the high pressure gas consumer or higher and supply the high pressure LNG compressed to the high pressure to the vaporizer 140 . In this embodiment, the high-pressure pump 120a compresses the LNG to be regenerated to 100 barg or more.

The vaporizer 140 vaporizes the high-pressure LNG by heat exchange, and the high-pressure regeneration gas vaporized in the vaporizer 140 is transferred to the high-pressure gas consumer.

In the vaporizer 140, the heating medium recovers the cold heat of the LNG to vaporize the LNG. The cooling heat medium, while vaporizing the LNG, is recovered to the working fluid condenser 440.

The LNG is vaporized by the vaporizer 140 to cool the heating medium, and the working fluid is condensed into the saturated liquid by using the LNG recovered by the heating medium condenser 440 to heat the heating medium. The temperature of the heating medium heated in the working fluid condenser 440 of this embodiment may be about 40 占 폚.

The heat medium heated while condensing the working fluid in the working fluid condenser 440 is circulated to the vaporizer 140 again.

The working fluid condensed in the working fluid condenser 440 is pressurized by the working fluid pump 440 to heat exchange with the cycle heating medium in the working fluid evaporator 240 to evaporate the working fluid into the superheated gas, And generates electric power by driving the turbine generator 430.

The load controller 600 controls the flow rate of the refrigerant to be supplied to the turbine generator 430 by using the temperature of the heating medium recovered by the working fluid condenser 440, the power generation load of the turbine generator 430, the temperature of the working fluid supplied to the turbine generator 430, The flow rate of the heat medium to be supplied to the vaporizer 140 or the trim heater 150 and the flow rate of the heat medium to be recovered to the working fluid condenser 440 bypassing both the vaporizer 140 and the trim heater 150 are controlled by controlling the valve 320 And controls the flow rate of the cycle heating medium to be supplied to the working fluid evaporator 420 and the flow rate of the cycle heating medium to bypass the working fluid evaporation path 450 by controlling the fifth flow control valve 510.

The regeneration gas discharge temperature of the vaporizer 140 or the trim heater 150 can be adjusted by adjusting the flow rate of the heating medium to be supplied to the vaporizer 140 or the trim heater 150. [ The flow rate of the heating medium to be supplied to the vaporizer 140 or the trim heater 150 may be adjusted using the regeneration gas discharge temperature of the vaporizer 140 or the trim heater 150. [

Further, by regulating the flow rate of the heat medium recovered to the working fluid condenser 440 by bypassing both the vaporizer 140 and the trim heater 150 along the second heating medium branch line GL2, the refrigerant discharged from the working fluid condenser 440 The temperature of the working fluid saturated liquid can be adjusted.

The flow rate of the heat medium recovered to the working fluid condenser 440 by bypassing both the vaporizer 140 and the trim heater 150 along the second heating medium branch line GL2 is changed according to the power generation load of the turbine generator 430 It can also be adjusted.

In this embodiment, when the temperature of the regeneration gas supplied from the vaporizer 140 to the high-pressure gas consumer is lower than the temperature required by the high-pressure gas consumer, the regeneration gas is further heated by the trim heater 150, It can be supplied to customers.

As the trim heater 150, the heating medium heated by the working fluid condenser 440 can be supplied as a heat source for further heating the regasification gas.

Therefore, according to the present invention, power is produced by using cold heat recovered while regenerating LNG, and utilized for supplying regeneration gas using the heat of condensation and the latent heat of condensation of the working fluid for producing electric power, It is possible to maximize the LNG regeneration efficiency without supplying any additional heat medium.

Next, referring to FIG. 2, an LNG regeneration system and method using an organic Rankine cycle according to a second embodiment of the present invention will be described.

In the second embodiment of the present invention, since the low-pressure evaporation gas is re-liquefied by using the cold heat of the evaporation gas and the temperature of the heat medium to be recovered as the heat medium circulation portion is controlled, the cold heat of the LNG to be re- And the first embodiment differs from the first embodiment in that it is condensed by use. The same configuration as that of the first embodiment can be applied even if the detailed description is omitted.

The LNG regeneration system according to the second embodiment of the present invention includes an LNG storage tank 100 for storing LNG; A regeneration unit for regenerating the LNG stored in the LNG storage tank 100 and supplying the LNG to the gas consumer; An evaporation gas processing unit for processing the evaporation gas generated by natural vaporization of LNG in the LNG storage tank 100; And a heat medium circulation unit for circulating the heat medium for regenerating the LNG. The LNG storage tank 100, the regeneration unit, the evaporation gas treatment unit, and the heat medium circulation unit of the present embodiment are connected to each other organically and operated organically.

It is preferable that the LNG storage tank 100 of the present embodiment is heat-treated so that the LNG can be stored while being maintained in a liquid state. In this embodiment, the LNG may be stored in the LNG storage tank 100 at about 1.1 bar to about -163 캜.

Although FIG. 2 illustrates only one LNG storage tank 100, at least one LNG storage tank 100 of the present embodiment may be provided.

Also, even if the LNG storage tank 100 is adiabatically treated, the LNG can be spontaneously vaporized by external heat penetration in the LNG storage tank 100 to generate boil-off gas (BOG). Therefore, the LNG storage tank 100 may be designed to withstand a pressure rise caused by the evaporation gas generated in the LNG storage tank 100 to a set pressure. When the internal pressure of the storage tank exceeds the set pressure, And may be designed to discharge the vaporized gas in the LNG storage tank 100 to the outside of the LNG storage tank 100. [ The evaporated gas discharged from the LNG storage tank 100 is processed in the evaporative gas processing section of this embodiment.

The LNG storage tank 100 of the present embodiment may be provided with an LNG supply pump (not shown) for transferring the LNG from the LNG storage tank 100 to the regeneration unit. The LNG supply pump may be a semi-submerged pump installed inside the LNG storage tank 100, or may be installed outside the LNG storage tank 100.

The regeneration unit of the present embodiment includes a high-pressure pump 120b for regenerating the LNG to be supplied to the gas consumer and supplying the compressed LNG to the vaporizer 140; And a carburetor 140 for exchanging heat between the compressed LNG compressed by the high-pressure pump 120b and the heat medium supplied from the heat medium circulation unit to vaporize the compressed LNG.

The LNG storage tank 100, the regeneration unit, and the gas demanding unit of the present embodiment are connected by a regeneration line (LL). The LNG is discharged from the LNG storage tank 100 by the LNG supply pump, regenerated while flowing along the regeneration line LL, and supplied to the gas consumer.

The high-pressure pump 120b of the present embodiment may be installed in a housing. In the housing in which the high-pressure pump 120b is installed, the LNG discharged from the LNG supply pump is accommodated, and a certain level is maintained.

The high-pressure pump 120b sucks the accommodated LNG while compressing the high-pressure pump 120b to a high pressure while maintaining a certain level in the housing. In the present embodiment, the high pressure is a pressure higher than the critical pressure of the LNG and may be a pressure required by the high pressure gas consumer. For example, the high pressure pump 120b of this embodiment can compress the LNG to greater than about 100 barg.

The heat exchange efficiency in the vaporizer 140 can be increased by compressing the LNG to be vaporized in this embodiment to a pressure higher than the critical pressure of the LNG. That is, the LNG compressed by the high-pressure pump 120b and transferred to the vaporizer 140 may be in a supercritical state.

The housing of this embodiment can serve as the suction drum 110 of the first embodiment described above. That is, in this embodiment, the high-pressure pump 120b is installed in the housing and sucks and compresses the LNG contained in the housing to stabilize the LNG flow transferred from the LNG storage tank 100 by the LNG supply pump, 120b can be smoothly operated.

In addition, the high-pressure pump 120b of this embodiment can be connected to the sixth evaporative gas branch line BL6 described later. The LNG contained in the housing may be vaporized by the operating heat of the high-pressure pump 120b or the like to generate an evaporative gas. In order to prevent the pressure in the housing from rising excessively due to the generation of the evaporative gas, when the pressure in the housing exceeds a certain pressure, the evaporated gas is discharged to the sixth evaporative gas branch line BL6. The sixth evaporation gas branch line BL6 is connected to the evaporation gas line BL as shown in Fig. 2, and the evaporation gas discharged from the high pressure pump 120b along the sixth evaporation gas branch line BL6 (BL) and transferred to a heat recovery apparatus 200 to be described later.

The high-pressure pump 120b of the present embodiment is configured such that a portion of the evaporated gas delivered to the heat recovery apparatus 200 along the evaporation gas line BL is supplied through the sixth evaporation gas branch line BL6, It may also serve as a recondenser for recondensing the evaporated gas by using the cold heat of the received LNG.

The evaporated gas recycled by the cold heat of the LNG in the housing is compressed by the high pressure pump 120b together with the LNG, regenerated in the vaporizer 140, and transferred to the high pressure gas consumer.

In this embodiment, the "LNG to be regasified" supplied to the high-pressure pump 120b can be interpreted as a concept including condensed evaporative gas in a liquid state condensed in the housing.

The vaporizer 140 of the present embodiment vaporizes LNG compressed at a high pressure in the high-pressure pump 120b by heat exchange with the heating medium.

In this embodiment, the heat medium to be heat-exchanged in the vaporizer 140 may be a glycol water circulating through a heat medium circulation section described later, and the compressed LNG is a high-pressure LNG compressed at about 100 barg or more in the high-pressure pump 120b .

The high-pressure LNG is vaporized by the heat exchanger in the vaporizer 140 and transferred to the high-pressure gas consumer. The glycol water vaporizes the high-pressure LNG and obtains the cold heat from the high-pressure LNG, and is supplied to the heat medium circulation unit again.

In this embodiment, the high-pressure gas consumer may be a regasification gas terminal installed on the land.

As described above, the high-pressure LNG transferred from the high-pressure pump 120a to the vaporizer 140 may be supercritical. Thus, in the present specification, "vaporizing" means not only a phase change from a liquid phase to a gaseous phase but also a phenomenon in which heat energy is transferred from a heat medium to an LNG, that is, LNG receives thermal energy from a heat medium, .

The regeneration unit of this embodiment further includes a preheater 130 for recovering cold heat before the compressed LNG compressed by the high pressure pump 120b is supplied to the evaporator 140. [

In the preheater 130 of the present embodiment, the compressed LNG to be regenerated, which is supplied to the vaporizer 140, is preheated.

The preheater 130 of this embodiment is connected to the regasification line LL and the refill lining line RL described later. That is, in the preheater 130, the compressed LNG supplied to the vaporizer 140 and the low-pressure evaporating gas flowing along the re-liquefaction line RL heat-exchange, the compressed LNG is heated, the low-pressure evaporation gas is cooled, Liquefied, or may be supercooled.

The compressed LNG heated in the preheater 130 is supplied to the vaporizer 140 and the low pressure evaporated gas cooled in the preheater 130 is returned to the LNG storage tank 100 in a liquid state.

According to the present embodiment, it is possible to improve both the regeneration efficiency of the compressed LNG and the re-liquefaction efficiency of the compressed evaporative gas by heat-exchanging the compressed LNG with the low-pressure evaporated gas before vaporizing the regenerated LNG and recovering the cold heat of the compressed LNG .

The regeneration unit of the present embodiment may further include a trim heater 150 that adjusts the temperature of the regeneration gas vaporized in the vaporizer 140 and transferred to the high-pressure gas consumer to a temperature required by the high-pressure gas consumer .

The trim heater 150 according to the present embodiment heats the regeneration gas vaporized in the vaporizer 140 to about 20 占 폚 or more, or the room temperature.

The trim heater 150 is connected to the vaporizer 140 and the high-pressure gas consumer via the regeneration line LL and is connected to the heat medium circulation unit via the heating medium line GL. That is, in the trim heater 150 of the present embodiment, the regeneration gas and the heating medium exchange heat, the regeneration gas is heated, and the heating medium is cooled.

The heating medium for heating the reground gas in the trim heater 150 may be a heating medium supplied from the heating medium circulating unit, in this embodiment, glycol water.

The regenerated gas having undergone the heat exchange in the trim heater 150 is supplied to the high-pressure gas consumer, and the heating medium is supplied to the heating medium circulating unit.

As described above, the LNG stored in the LNG storage tank 100 of the present embodiment is supplied to the high-pressure pump 120b by the LNG supply pump, compressed by the high-pressure pump 120b to a pressure required by the high-pressure gas consumer, The cold heat is recovered in the evaporator 130, vaporized in the evaporator 140, temperature is controlled in the trim heater 150, and is transferred to the high-pressure gas consumer.

The LNG storage tank 100, the high-pressure pump 120b, the preheater 130, the vaporizer 140, the trim heater 150 and the high-pressure gas consumer in the present embodiment are connected by the regeneration line LL, Is regenerated and transported from the LNG storage tank 100 to the high-pressure gas consumer along the line LL.

The evaporation gas processing unit of the present embodiment includes an evaporation gas compression unit for compressing the evaporation gas and supplying it to the gas consumer; And a re-liquefaction unit for re-liquefying the compressed evaporative gas and recovering the recovered liquefied gas to the LNG storage tank (100).

The evaporation gas compression unit includes a low pressure compressor (210) for compressing the evaporation gas to a pressure required by the consumer of the low pressure gas; And a high-pressure compressor (220) for compressing the evaporated gas to a pressure required by the high-pressure gas consumer.

In this embodiment, the low-pressure gas consumer may be a gas consumer in-ship or a gas consumer on-board or off-shore. For example, the low pressure gas consumer may be a low pressure gas injection engine requiring a low pressure gas of about 2 bar to 8 bar, such as an inboard DFDE engine.

In addition, in this embodiment, the high-pressure gas consumer can be a gas consumer in-ship or a off-shore or terrestrial gas consumer. For example, the high pressure gas consumer may be a high pressure gas injection engine requiring a high pressure gas of about 150 bar to 300 bar, such as onshore gas terminals, ME-GI engines onboard. In this embodiment, it is assumed that the high-pressure gas consumer of about 100 bar is a terrestrial gas terminal.

The high-pressure compressor 220 of this embodiment may not be installed as required. When the high-pressure compressor 220 and the low-pressure compressor 210 are installed together, the low-pressure compressor 210 compresses the evaporation gas to a pressure required by the low-pressure gas compressor and supplies the compressed gas to the consumer in the low-pressure gas, It is possible.

2, the high-pressure compressor 220 is installed at the rear end of the low-pressure compressor 210 as an example. However, the present invention is not limited thereto, and the high-pressure compressor 220 and the low-pressure compressor 210 may be installed in parallel. In this embodiment, it is assumed that the low-pressure compressor 210 and the high-pressure compressor 220 are connected in series as shown in Fig. 2. In this embodiment, the low-pressure compressor 210 and the high- The low-pressure evaporation gas may be branched and supplied to at least one of the low-pressure gas consumer, the high-pressure compressor 220, and the re-condenser.

The liquefaction portion of the present embodiment includes a heat recovery device 200 for recovering the cold and hot of the evaporation gas supplied from the LNG storage tank 100 to the evaporation gas compression portion; An expansion valve (250) for reducing the pressure of the evaporated gas from which cold heat has been recovered to an internal pressure or lower of the LNG storage tank (100); And a gas-liquid separator 260 for separating the gas-liquid mixture generated while passing through the expansion valve 250 and supplying the liquid-state re-liquefied vaporized gas to the LNG storage tank 100.

The LNG storage tank 100, the evaporation gas processing unit, the low-pressure gas consumer, and the high-pressure gas consumer in the present embodiment can be connected by the evaporation gas line BL.

The evaporation gas line BL of this embodiment includes a plurality of branch lines which branch from the evaporation gas line BL. 2, a plurality of evaporative gas branch lines are branched at the downstream end of the low-pressure compressor 210. However, the present invention is not limited thereto. A plurality of evaporative gas branch lines may be branched at a rear end of the LNG storage tank 100 and a front end of the low pressure compressor 210 and a low pressure compressor 210 may be selectively installed at each branch line.

First, the evaporation gas line BL of the present embodiment connects the LNG storage tank 100, the heat recovery apparatus 200, and the low-pressure compressor 210 as shown in FIG. The evaporated gas discharged from the LNG storage tank 100 is supplied to the heat recovery apparatus 200 along the evaporation gas line BL and the evaporated gas recovered from the heat recovery apparatus 200 is supplied to the low pressure compressor 210, And is compressed to a low pressure.

Since the evaporated gas is supplied from the LNG storage tank 100 to the low-pressure compressor 210 after the cold heat is recovered in the heat recovery apparatus 200, the low-pressure compressor 210 and the high-pressure compressor 220 are supplied to the high- It may not be provided as a compressor.

The evaporation gas line BL of the present embodiment connects the low pressure compressor 210 and the high pressure compressor 220 so that the low pressure evaporation gas is compressed to a high pressure by the high pressure compressor 220, A second evaporative gas branch line BL2; A third evaporative gas branch line BL3 connecting the low-pressure compressor 210 to the low-pressure gas consumer and allowing the low-pressure evaporated gas to be transferred to the low-pressure gas consumer; And a re-liquefaction line (RL) that connects the low-pressure compressor (210) and the re-liquefaction section, and re-liquefies the low-pressure evaporated gas in the re-liquefaction section to be recovered to the LNG storage tank (100).

That is, in the present embodiment, the evaporation gas generated in the LNG storage tank 100 is supplied to the housing of the high-pressure pump 120b along the sixth evaporation gas branch line BL6, or the evaporation gas line BL, Pressure compressor 210 to be compressed to a low pressure.

In addition, in this embodiment, the low-pressure evaporated gas compressed by the low-pressure compressor 210 is further compressed by the high-pressure compressor 220 along the second evaporative gas branch line and supplied to the high-pressure gas consumer, BL3 to the LNG storage tank 100 or may be re-collected along the re-liquefaction line RL to be recovered to the LNG storage tank 100. [

The redistribution line RL of this embodiment is branched from the evaporation gas line BL at the downstream end of the low pressure compressor 210 and is connected to the heat recovery unit 200, the preheater 130, the expansion valve 250, the gas-liquid separator 260, And the LNG storage tank 100 are connected to each other.

The heat recovery apparatus 200 of this embodiment is connected to the evaporation gas line BL, the refill lining line RL and the heating medium line GL described later. That is, in the heat recovery apparatus 200 of this embodiment, the evaporation gas supplied from the LNG storage tank 100 to the low-pressure compressor 210 along the evaporation gas line BL; A low-pressure evaporating gas to be re-liquefied, which is compressed in the low-pressure compressor 210 and branched to the re-liquefaction line RL; And a heating medium which is cooled and recovered as a heat medium circulation part while heat-exchanging heat in the regeneration part along the heating medium line (GL).

In the heat recovery apparatus 200, the evaporation gas is recovered by the heat exchange, and the low-pressure evaporation gas to be re-liquefied and the heat medium recovered as the heat medium circulation unit are cooled by the cooling heat of the evaporation gas.

The re-liquefaction line (RL) of the present embodiment is arranged so that the low-pressure evaporation gas supplied to the heat recovery apparatus 200 along the re-liquefaction line RL bypasses the heat recovery apparatus 200, And a first redistribution branch line (RL1) branched to be merged into the flow.

A third flow control valve 230 is installed at a point where the first re-liquefaction branch line RL1 branches from the re-liquefaction line RL.

The load controller 600, which will be described later, controls the third flow rate control valve 230 in accordance with the power generation load of the heat medium circulation section and the temperature of the heat medium recovered to the heat medium circulation section, which will be described later. By regulating the third flow rate control valve 230, the flow rate of the low-pressure evaporation gas supplied to the heat recovery apparatus 200 can be controlled, thereby adjusting the re-liquefied flow rate, the temperature of the heat medium recovered to the heat medium circulation unit, .

The low pressure evaporative gas flowing along the redistribution line RL of this embodiment is supplied to the heat recovery apparatus 200 and is supplied to the heat recovery apparatus 200 from the LNG storage tank 100 along the evaporation gas line BL Cooled by the cooling heat of the supplied evaporating gas and then supplied to the preheater 130 to be further cooled by the compressed LNG to be regenerated supplied to the vaporizer 140 along the regeneration line LL.

In the preheater 130 of this embodiment, the regasification line LL and the refill lining line RL are connected.

In the preheater 130 of the present embodiment, a low-pressure evaporation gas flowing along the redistribution line RL and a high-pressure LNG to be regenerated flowing along the regasification line LL heat-exchange. By the heat exchange in the preheater 130, the low-pressure evaporation gas flowing along the refill lining line RL is cooled and the high-pressure LNG flowing along the re-gasification line LL is heated.

The low pressure evaporative gas stream cooled in the preheater 130 is fed to the expansion valve 250 and the compressed LNG stream heated in the preheater 130 is fed to the vaporizer 140.

The state of the low-pressure evaporation gas supplied to the preheater 130 along the re-liquefaction line RL may be a gas, a liquid or a gas-liquid mixture. Thus, the fact that the low-pressure evaporation gas is cooled in the preheater 130 can be a concept including liquefaction (condensation), cooling (temperature drop) and supercooling of the low-pressure evaporation gas.

In addition, the redistribution line (RL) of this embodiment is provided with a second redistribution line (R1) connected to the downstream side of the preheater (130) to bypass the preheater (130) And a branch line RL2.

A fourth flow control valve 240 is installed at a point where the second redistribution branch line RL2 branches from the redistribution line RL.

The load controller 600 controls the fourth flow rate control valve 240 in accordance with a power generation power load of the heating medium circulation section and a temperature of the heating medium recovered to the heating medium circulation section, which will be described later. The flow rate of the remanufacturing flow to be further cooled in the preheater 130 along the remanufacturing line RL and the flow rate of the remanufacturing flow to be further cooled in the preheater 130 are controlled by controlling the fourth flow control valve 240, And the flow rate of the re-liquefied flow to bypass.

According to the present embodiment, in the preheater 130, the cold heat of the compressed LNG to be regasified is recovered, and cold heat is supplied to the low-pressure evaporative gas flow flowing along the re-liquefaction line RL, The regeneration efficiency of the LNG can be improved and the cooling or heating load of the heat exchangers constituting the regeneration section and the re-liquidation section can be lowered.

The low-pressure evaporative gas stream that has passed through the heat recovery apparatus 200 and the preheater 130 while passing through the expansion valve 250 is depressurized to a pressure suitable for recovery to the LNG storage tank 100.

The expansion valve 250 of the present embodiment may be a line-thomson valve or an inflator, and the entire amount of the evaporated gas may be in a liquid state while passing through the expansion valve 250, or a flash gas may be generated to form a gas-liquid mixture. The flow passing through the expansion valve 250 is supplied to the gas-liquid separator 260 to be subjected to gas-liquid separation, and the separated liquid-state re-liquefied vaporized gas is recovered to the LNG storage tank 100 along the re-liquefaction line RL .

The gas-liquid separator 260 of the present embodiment is arranged so that the gas-liquid separator 260 is connected to the evaporation gas line BL, more specifically, from the gas-liquid separator 260 to the rear end of the LNG storage tank 100, And a fourth evaporative gas branch line BL4 connected to the fourth evaporative gas branch line BL4.

The gaseous non-resolidified vaporized gas separated in the gas-liquid separator 260 is merged into the vaporized gas line BL along the fourth vaporized gas branch line BL4. More specifically, the non-refluxed vaporized gas separated in the gas-liquid separator 260 is joined to the vaporized gas stream supplied from the LNG storage tank 100 to the heat recovery apparatus 200.

The gas-liquid separator 260 of this embodiment is further connected to a fifth evaporative gas branch line BL5 connecting a mist separator (not shown) and a gas-liquid separator 260, not shown.

The mist separator is installed at the front ends of the low pressure compressor 210 and the high pressure compressor 220 and separates the mist component from the evaporation gas introduced into the low pressure compressor 210 and the high pressure compressor 220.

When mist components are mixed in the evaporation gas supplied to the low-pressure compressor 210 and the high-pressure compressor 220, problems such as causing damage to the driving portion of the compressor occur. Therefore, mist components contained in the evaporation gas before being supplied to the compressor And a mist separator for separating and removing the mist separator.

The fifth evaporation gas branch line (BL) of this embodiment allows the mist separator to supply the mist component separated from the evaporation gas to the gas-liquid separator (260).

In addition, the evaporation gas line BL of this embodiment may further include a sixth evaporation gas branch line BL6 branched from the evaporation gas line BL and connected to the high-pressure pump 120b.

The sixth evaporative gas branch line BL6 serves as a suction drum for maintaining the high pressure pump 120b at a constant pressure so that the high pressure pump 120b, To the evaporation gas line (BL), or to supply the evaporation gas from the evaporation gas line (BL) to the housing of the high-pressure pump (120b).

The heating medium circulating unit of this embodiment includes a heating medium line GL connecting the heating medium circulating unit and the regrounding unit; A heating medium circulation pump 310 for pressurizing the heating medium such that the heating medium flows along the heating medium line GL; And a power generation unit for recovering cold and heat of the heat medium which has been cooled by the heat exchange in the regeneration unit.

In the present embodiment, the heating medium flows along the heating medium line GL, recovers the cold heat of the LNG while exchanging heat with the LNG in the regeneration section, and the cooling medium, which is cooled by heat exchange with the LNG, The heating medium whose temperature has risen is pressurized by the heat medium circulation pump 310 and supplied to the regeneration unit.

In this embodiment, the heating medium is exemplified by glycol water.

The heat medium circulation part of the present embodiment is provided between the power generation part and the heat medium circulation pump 310 and accommodates the heat medium discharged from the power generation part to heat the heat medium supplied from the power generation part to the heat medium circulation pump 310, And an expansion vessel (340) for holding the expansion vessel (340).

According to the present embodiment, since the expansion valve 340 is provided to serve as a buffer for relieving the volume change of the glycol water supplied from the power generation section to the heat medium circulation pump 310, the heat medium circulation pump The glycol water supplied to the circulation pump 310 can maintain the head at a pressure higher than a certain pressure and cavitation of the suction side of the circulation pump 310 can be prevented.

The heating medium line GL of the present embodiment includes a first heating medium branch line GL1 branched from the heating medium line GL and connected to the trim heater 150. [ The heating medium of this embodiment is supplied to the trim heater 150 along the first heating medium branch line GL1 and is cooled by the trim heater 150 while vaporizing the LNG to circulate to the power generation section.

That is, the heating medium circulating through the heating medium line GL by the heating medium circulation pump 310 can be used as a heat source of the vaporizer 140 of the regeneration unit or the trim heater 150. In this embodiment, the temperature of the heat medium supplied from the heat medium circulation part to the regeneration part may be about 40 占 폚.

The heating medium is supplied to the vaporizer 140 or the trim heater 150 along the heating medium line GL and collects the cold heat while exchanging heat with the LNG in the vaporizer 140 or the trim heater 150 and is recovered as a power generation portion.

The heating medium line GL of the present embodiment may include a second heating medium branch line GL2 branched from the heating medium line GL and connected so that the heating medium bypasses the regeneration portion and is returned to the heating medium circulation portion.

The flow rate of the heating medium supplied to the vaporizer 140 as the three-way valve, the flow rate of the heat medium supplied to the trim heater 150, And a first flow control valve 320 for controlling the flow rate of the heat medium and the flow rate of the heat medium branched to the second heating medium branch line GL2.

The temperature of the heating medium flowing along the heating medium line GL is measured in the heating medium line GL through which the heating medium is recovered from the regeneration section to the heating medium circulation section and the first temperature And a measurement unit TT1.

The load controller 600, which will be described later, adjusts the opening amount of the first flow control valve 320 to adjust the temperature of the heat medium recovered to the power generation section in accordance with the temperature measurement value of the heat medium recovered to the power generation section and the power generation load of the power generation section .

The heating medium line GL according to the present embodiment is connected to the heat recovery apparatus 200 from the rear end of the vaporizer 140 and the trim heater 150. That is, in the present embodiment, the heat medium recovered from the LNG or regenerated gas by heat exchange in the vaporizer 140 or the trim heater 150 is recovered from the LNG storage tank 100 to the low- The cold heat of the evaporation gas supplied to the evaporator 210 is recovered and recovered to the power generator.

The heating medium line GL of the present embodiment is arranged so that the heating medium recovered to the power generation section bypasses the heat recovery apparatus 200 and flows into the heat recovery apparatus 200 through the third heating medium branch line (GL3).

At a point where the third heating medium branch line GL3 branches from the heating medium line GL, a second flow control valve 330 is installed.

The load controller 600 controls the second flow rate control valve 330 to adjust the flow rate of the heat medium to be further cooled in the heat recovery apparatus 200 among the heat medium recovered to the power generation section, .

The power generation portion of the present embodiment is an example of an organic Rankine Cycle in which electric power is generated using heat recovered by heat exchange with the LNG by the heat medium and recovery of the heat recovered by the heat medium is performed to heat the heat medium again. have.

The power generating portion of this embodiment includes a working fluid pump 410 for circulating the working fluid of the organic Rankine cycle; A working fluid evaporator (420) for evaporating the working fluid; A turbine generator 430 including a turbine driven using a working fluid evaporated in the working fluid evaporator 420 and a generator converting the driving force of the turbine into electric energy; And a working fluid condenser 440 for condensing the working fluid expanded while passing through the turbine generator 430 by using cold heat of the heat medium recovered from the LNG in the regeneration portion.

The working fluid pump 410, the working fluid evaporator 420, the turbine generator 430, and the working fluid condenser 440 of this embodiment are connected by a working fluid line WL through which the working fluid flows.

Further, the working fluid condenser 440 is connected to the working fluid line WL and the heating medium line GL. That is, in the working fluid condenser 440, the working fluid and the heating medium exchange heat, the working fluid condenses, and the heating medium is heated.

The working fluid condensed in the working fluid condenser 440 is circulated to the working fluid pump 410 along the working fluid line WL and the heating medium heated in the working fluid condenser 440 is circulated along the heating medium line GL, And is circulated to the pump 310.

The working fluid evaporator 420 is connected to a working fluid line (WL) through which the working fluid flows and a cycle heating medium line (HL) through which the working fluid circulates by heat exchange with the working fluid to evaporate the working fluid. That is, in the working fluid evaporator 420, the working fluid and the cycle heating medium exchange heat, the working fluid evaporates, and the cycle heating medium is cooled.

The working fluid line WL is provided with a second temperature measuring unit TT2 for measuring the temperature of the working fluid supplied from the working fluid evaporator 420 to the turbine generator 430 and for transmitting the measured temperature value to the load controller 600 ) May be provided.

A fifth flow control valve 510 is provided in the cycle heating medium line HL to regulate the flow rate of the cycle heating medium supplied from the unillustrated cycle heating medium supply unit to the working fluid evaporator 420.

The load controller 600 adjusts the amount of opening of the fifth flow control valve 510 according to the measured value of the second temperature measurement unit TT2 and the power generation load of the turbine generator 430. [ The flow rate of the cycle heating medium supplied to the working fluid evaporator 420, that is, the temperature of the working fluid superheated gas formed in the working fluid evaporator 420, is controlled by adjusting the amount of opening of the fifth flow control valve 510. That is, the load controller 600 controls the working fluid to be supplied to the turbine generator 430 at a temperature suitable for the power load to be produced by the turbine generator 430.

The cycle heating medium line HL of the present embodiment may further include a first cycle heating medium branch line HL1 that branches from the cycle heating medium line HL and is formed such that the cycle heating medium bypasses the working fluid evaporator 420 .

A fifth flow control valve 510 may be installed at a point where the first cycle heating medium branch line HL1 is branched from the cycle heating medium line HL.

A part of the cycle heating medium supplied from the cycle heating medium supply section to the working fluid evaporator 420 under the control of the fifth flow control valve 510 is supplied to the working fluid evaporator 420 along the first cycle heating medium branch line HL1 It can be bypassed and recycled to the cycle heating medium supply section.

The working fluid superheated gas becomes a low pressure saturated liquid while the turbine generator 430 drives the turbine, and a working fluid in a low pressure saturated liquid state is supplied to the working fluid condenser 440.

The LNG regeneration system according to the present embodiment includes a first flow control valve 320, a second flow control valve 330, a third flow control valve 230, a fourth flow control valve 240, The control valve 510 is controlled to control the temperature of the heat medium flowing along the heating medium line GL and the temperature of the working fluid of the power generation section flowing along the working fluid line WL, The temperature of the cycle heating medium flowing along the cycle heating medium line HL, and the load controller 600 for adjusting the flow state of the evaporating gas flowing along the re-liquefaction line RL.

Hereinafter, the operation principle of the LNG regeneration system according to the second embodiment of the present invention will be described.

The LNG to be regasified is supplied from the LNG storage tank 100 to the high pressure pump 120b by operating the LNG supply pump. At this time, the LNG discharged from the LNG supply pump is accommodated in the housing of the high-pressure pump 120b. The flow rate of the LNG supplied from the LNG storage tank 100 to the high-pressure pump 120b can be controlled according to the regeneration gas flow rate required by the high-pressure gas consumer or the level and the internal pressure in the housing. Also, the level of the housing and the internal pressure are kept constant. The level and the internal pressure of the housing are controlled by adjusting the operating state of the LNG supply pump and the high-pressure pump 120b and the flow rate of the evaporative gas supplied to the housing through the sixth evaporative gas branch line BL6 or discharged from the housing .

Pressure pump 120b to compress the LNG to be regenerated at a pressure required by the high-pressure gas consumer or higher, and to supply the high-pressure LNG compressed at high pressure to the pre-heater 130. [ In this embodiment, the high-pressure pump 120b compresses the LNG to be regenerated to 100 barg or more.

The preheater 130 exchanges heat between the LNG compressed by the high pressure pump 120b and regenerated by the heat recovery apparatus 200 and the low pressure evaporating gas flowing along the re-liquefaction line RL, And the evaporation gas to be re-liquefied is cooled.

The compressed LNG heated in the preheater 130 is supplied to the vaporizer 140.

The vaporizer 140 vaporizes the high-pressure LNG by heat exchange, and the high-pressure regeneration gas vaporized in the vaporizer 140 is further heated in the trim heater 150 using the heating medium to supply it to the high-pressure gas consumer.

In this embodiment, when the temperature of the regeneration gas supplied from the vaporizer 140 to the high-pressure gas consumer is lower than the temperature required by the high-pressure gas consumer, the regeneration gas is further heated by the trim heater 150, It can be supplied to customers.

In the vaporizer 140 and the trim heater 150, the heating medium recovers the cold heat of the LNG to vaporize the LNG. The heat medium that has been cooled while exchanging heat with the LNG is further cooled by the cooling heat of the evaporation gas in the heat recovery apparatus 200 and is recovered to the working fluid condenser 440.

The load controller 600 controls the second flow rate control valve 330 to control the temperature of the heat medium recovered to the working fluid condenser 440 by controlling the flow rate of the heat medium to be further cooled in the heat recovery apparatus 200 can do. The temperature of the heat medium recovered by the working fluid condenser 440 can be adjusted according to the power generation load of the power generation section.

The LNG is vaporized by the vaporizer 140 to cool the heating medium, and the working fluid is condensed into the saturated liquid by using the LNG recovered by the heating medium condenser 440 to heat the heating medium. The temperature of the heating medium heated in the working fluid condenser 440 of this embodiment may be about 40 占 폚.

The heat medium heated while condensing the working fluid in the working fluid condenser 440 is circulated to the vaporizer 140 again.

The working fluid condensed in the working fluid condenser 440 is pressurized by the working fluid pump 440 to heat exchange with the cycle heating medium in the working fluid evaporator 240 to evaporate the working fluid into the superheated gas, And generates electric power by driving the turbine generator 430.

The load controller 600 controls the flow rate of the refrigerant to be supplied to the turbine generator 430 by using the temperature of the heating medium recovered by the working fluid condenser 440, the power generation load of the turbine generator 430, the temperature of the working fluid supplied to the turbine generator 430, The flow rate of the heat medium to be supplied to the vaporizer 140 or the trim heater 150 and the flow rate of the heat medium to be recovered to the working fluid condenser 440 bypassing both the vaporizer 140 and the trim heater 150 are controlled by controlling the valve 320 And controls the flow rate of the cycle heating medium to be supplied to the working fluid evaporator 420 and the flow rate of the cycle heating medium to bypass the working fluid evaporation path 450 by controlling the fifth flow control valve 510.

The regeneration gas discharge temperature of the vaporizer 140 or the trim heater 150 can be adjusted by adjusting the flow rate of the heating medium to be supplied to the vaporizer 140 or the trim heater 150. [ The flow rate of the heating medium to be supplied to the vaporizer 140 or the trim heater 150 may be adjusted using the regeneration gas discharge temperature of the vaporizer 140 or the trim heater 150. [

Further, by regulating the flow rate of the heat medium recovered to the working fluid condenser 440 by bypassing both the vaporizer 140 and the trim heater 150 along the second heating medium branch line GL2, the refrigerant discharged from the working fluid condenser 440 The temperature of the working fluid saturated liquid can be adjusted.

The flow rate of the heat medium recovered to the working fluid condenser 440 by bypassing both the vaporizer 140 and the trim heater 150 along the second heating medium branch line GL2 is changed according to the power generation load of the turbine generator 430 It can also be adjusted.

Therefore, according to the present invention, power is produced by using cold heat recovered while regenerating LNG, and utilized for supplying regeneration gas using the heat of condensation and the latent heat of condensation of the working fluid for producing electric power, It is possible to maximize the LNG regeneration efficiency without supplying any additional heat medium.

The evaporated gas generated in the LNG storage tank 100 is recovered by heat exchange between the low-pressure evaporative gas to be re-liquefied and the heat medium recovered as the heat medium circulation unit in the heat recovery apparatus 200, Pressure gas is supplied to the customer, the low-pressure evaporative gas remaining after being supplied to the low-pressure gas consumer is branched to the second evaporative gas branch line BL2, the high-pressure compressor 220 compresses the high- Or is re-liquefied and recovered to the LNG storage tank 100. [

The low-pressure evaporation gas to be re-liquefied is supplied to the heat recovery apparatus 200, cooled by the cold heat of the evaporation gas discharged from the LNG storage tank 100, and supplied to the pre-heater 130 to cool the LNG And is further lowered in temperature while being thermally expanded to a pressure for supplying the LNG storage tank 100 at the expansion valve 250.

The load controller 600 controls the third flow rate regulating valve 230 to regulate the flow rate of the low-pressure evaporation gas to be cooled in the heat recovery apparatus 200.

For example, when the flow rate of the low-pressure evaporating gas bypassing the heat recovery apparatus 200 is increased by controlling the third flow regulating valve 230, that is, the flow rate of the low-pressure evaporating gas branched to the first re- When the flow rate is increased, the temperature of the heating medium to be cooled in the heat recovery apparatus 200 is lowered, and thus the power generation efficiency of the turbine generator 600 is increased.

The evaporated gas that has passed through the expansion valve 250 is supplied to the gas-liquid separator 260 to be subjected to gas-liquid separation, and the re-liquefied vaporized gas in the liquid state is supplied to the LNG storage tank 100, Is joined to the evaporative gas stream supplied from the LNG storage tank (100) to the heat recovery apparatus (200).

Accordingly, compared with the first embodiment, the suction drum having the role of the recondenser is eliminated, and the heat recovery device 200, the preheater 130, the expansion valve 150, and the gas-liquid separator 260 It is possible to provide the evaporator 140 with a small regeneration capacity by not liquefying the evaporation gas by mixing with the LNG but by re-liquefying the evaporator 140. When the regeneration is not carried out, The entire evaporation gas can be recovered by re-liquefaction.

Also, the flow rate of the evaporative gas in the gaseous state that is not re-liquefied and separated by the gas-liquid separator 260 can be adjusted by adjusting the flow rate of the low-pressure evaporation gas supplied to the heat recovery apparatus 200. For example, even when the regeneration is not performed or the regeneration capacity is small, even if the flow rate of the evaporation gas supplied to the heat recovery apparatus 200 is adjusted, it is possible to sufficiently provide cold heat in the heat recovery apparatus 200 , The power generation load of the turbine generator 430 can be maintained at a constant level or higher.

It will be apparent to those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or scope of the invention as defined in the appended claims. . Therefore, the above-described embodiments are to be considered as illustrative rather than restrictive, and thus the present invention is not limited to the above description, but may be modified within the scope of the appended claims and equivalents thereof.

100: LNG storage tank
110: Suction drum
120a, 120b: high-pressure pump
130: preheater
140: vaporizer
150: Trim heater
200: Heat recovery device
210: Low pressure compressor
220: High Pressure Compressor
230: Third flow control valve
240: fourth flow control valve
250: expansion valve
260: gas-liquid separator
310: Heat medium circulation pump
320: first flow control valve
330: second flow control valve
340: expansion valve
410: Working fluid pump
420: working fluid vaporizer
430: Turbine generator
440: Working fluid condenser
510: fifth flow control valve
600: load controller
TT1: first temperature measuring unit
TT2: second temperature measuring unit
LL: Revitalization line
BL: Evaporation gas line
RL: Re-liquefaction line
GL: Heat medium line
WL: working fluid line
HL: Cycle heat medium line

Claims (15)

A re-liquidifying unit for re-liquefying and recovering the evaporated gas generated by spontaneously vaporizing the liquefied gas;
A regeneration unit for vaporizing the liquefied gas and supplying the vaporized liquefied gas to a demand site for regasification gas; And
And a heating medium circulation unit for supplying the heating medium to the regeneration unit and recovering the heating medium from which the cold gas is recovered from the liquefied gas in the regeneration unit to produce electric power,
The re-liquefier may comprise:
A compressor for compressing the evaporated gas; And
And a heat recovery device for recovering the cold heat of the pre-compression evaporation gas to cool the compression evaporation gas and the heat medium recovered to the heat medium circulation part. The method according to claim 1,
The re-
A high pressure pump for compressing the liquefied gas to be vaporized;
A preheater for recovering the cold heat of the compressed liquefied gas and cooling the compressed evaporative gas cooled in the heat recovery unit; And
And a vaporizer for vaporizing the compressed liquefied gas recovered in the preheater by heat exchange with the heat medium, wherein the liquefied gas regeneration system uses an organic Rankine cycle. The method of claim 2,
The heat medium circulation unit includes:
And a power generation portion in which the working fluid circulates,
The power generation unit includes:
A working fluid condenser for supplying the working fluid with the cold heat recovered by the heating medium;
A working fluid evaporator for generating a working fluid condensed in the evaporating gas condenser as a superheated gas; And
And a turbine generator for driving the turbine with the superheated gas and producing electric power,
And a heating medium supply pump for supplying the heating medium heated by the heat of condensation of the working fluid to the regeneration unit while the cold heat of the recovered heat medium is recovered as the working fluid in the working fluid condenser, Gas regeneration system. The method of claim 3,
A third flow control valve for controlling the flow path of the compressed evaporative gas so that the compressed evaporative gas bypasses the heat recovery device and joins to the downstream end of the heat recovery device; And
And a load controller for controlling the temperature of the heat medium recovered to the power generator by controlling the third flow rate control valve according to a power generation load of the turbine generator. The method of claim 4,
The re-liquefier may comprise:
An expansion valve for reducing the pressure of the compressed evaporative gas while passing through at least one of the heat recovery device and the preheater; And
And a gas-liquid separator for gas-liquid separating the reduced-pressure evaporative gas passed through the expansion valve,
Liquid separator and the liquid-state re-liquefied vapor gas separated from the gas-liquid separator is recovered to the liquefied gas storage tank. The method of claim 5,
And a fourth evaporative gas branch line for merging the gaseous re-liquefied evaporated gas separated in the gas-liquid separator into an evaporated gas stream supplied to the heat recovery apparatus,
Wherein the flow rate of the evaporative gas flowing through the fourth evaporative gas branch line is controlled by the control of the third flow rate regulating valve. The method of claim 3,
And a trim heater that heats the regasification gas by heat exchange with the heating medium when the regasification gas vaporized in the vaporizer is lower than a temperature required by the gas consumer, Fire system. The method according to claim 3 or 7,
A first flow rate control valve for controlling the flow path of the heating medium supplied to the regeneration unit and the flow path of the heating medium recovered to the heating medium circulation unit by bypassing the regeneration unit; And
And a load controller for controlling the temperature of the heat medium recovered to the heat medium circulation unit by controlling the first flow rate control valve according to a power generation load of the turbine generator. The method of claim 2,
A sixth evaporation gas branch line for joining the evaporation gas generated from the high pressure pump to the evaporation gas flow supplied to the heat recovery apparatus or for introducing the evaporation gas flow supplied to the heat recovery apparatus to the high pressure pump Wherein the liquefied gas regeneration system comprises an organic Rankine cycle. The liquefied gas is vaporized by heat exchange with the heating medium to supply it to the demand of the regasified gas,
The vaporized gas generated by natural vaporization of the liquefied gas is recovered by liquefaction,
And recovering the cooled heat medium to the heat medium circulation part while vaporizing the liquefied gas to produce electric power,
In the heat medium circulation part, the heat medium is heated while the cold heat is recovered for producing electric power,
And the heated heating medium is circulated to regenerate the liquefied gas. The method of claim 10,
The evaporation gas is compressed,
And recovering the cold heat of the pre-compression evaporation gas to cool the heating evaporation gas and the heat medium recovered to the heat medium circulation section. The method of claim 11,
Adjusting the flow rate of the compressed evaporative gas to be heat-exchanged with the pre-compression evaporative gas in accordance with the power production load,
And regulating the temperature of the heat medium recovered to the heat medium circulation unit according to the flow rate of the pre-compression evaporation gas. The method of claim 10,
Wherein the heating is performed by heat exchange with the heating medium when the temperature of the regeneration gas vaporized by the heat exchange with the heating medium is lower than the temperature required by the regeneration gas consumer. 14. The method of claim 13,
Depending on the power production load
The flow rate of the heating medium to be vaporized, the flow rate of the heating medium to be heated in the regeneration gas, and the flow rate of the heating medium to be circulated to the heating medium circulation section without heat exchange with the liquefied gas or regeneration gas,
And regulating the temperature of the heat medium recovered to the heat medium circulation unit, using the organic Rankine cycle. The method of claim 10,
Compressing the liquefied gas to be vaporized,
The compressed liquefied gas is preheated by heat exchange with a compressed evaporation gas cooled by heat exchange with the pre-compression evaporation gas,
And the preheated compressed liquefied gas is vaporized by heat exchange with the heating medium.

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