WO2016178555A1

WO2016178555A1 - Lng optimum control reliquefaction system for recovering lng low-temperature waste heat generated during lng vaporization

Info

Publication number: WO2016178555A1
Application number: PCT/KR2016/004973
Authority: WO
Inventors: 양원돈; 이성춘; 이동건; 이대진
Original assignee: 유진초저온(주)
Priority date: 2015-12-12
Filing date: 2016-05-12
Publication date: 2016-11-10
Also published as: CN107124894B; KR101621933B1; CN107124894A

Abstract

The present invention is configured to: supply gaseous LNG to a gaseous LNG consumer while allowing liquid LNG to discharge cold energy through a heat exchanger for a load of a cold energy supply unit for a warehouse, so as to supply a sufficient amount of the gaseous LNG within an LNG storage tank, thereby increasing the temperature of or vaporizing the liquid LNG; allow the LNG with an elevated temperature or vaporized to be supplied to a gaseous LNG consumer supply line, thereby expanding the cold energy use and dissemination of the LNG; and optimally control and reliquefy the flux of the liquid LNG and gaseous LNG, thereby economically recovering the low-temperature waste heat of the LNG generated during LNG vaporization.

Description

LNG optimal control reliquefaction system for LNG low temperature waste heat recovery generated during LNG vaporization process

The present invention relates to a LNG optimum control reliquefaction system for LNG low temperature waste heat recovery generated during the LNG vaporization process.

LNG is being used as environmentally friendly energy, and LNG bases are being constructed on the coast where a number of LNG liquefied gas storage tanks are installed.

The LNG liquefied gas storage tank stores liquefied LNG gas, and vaporizes the liquefied gas in order to supply an appropriate amount of LNG gas to the demand destination (pipes such as city gas).

In order to vaporize LNG liquefied gas, a vaporizer is generally used, and a vaporizer is largely divided into a seawater vaporizer and a combustion vaporizer. The most economical seawater vaporizer is a liquid LNG that is formed by exchanging heat by receiving water (sea water) from the outside. After the change, the gas is sent out at room temperature.

In order to operate such a carburetor, a huge amount of water is required, and a pump for supplying such a large amount of water is required, resulting in enormous power consumption.

As a method for supplying water to the carburetor as described above, a separate water tank may be provided and water stored in the water tank may be circulated to the carburetor, but most of the water is directly vaporized using the sea water.

In addition, even when circulating the water stored in the tank to the carburetor, a heater for heating the water stored in the tank is required, and the power required to drive the heater, a problem that the enormous power consumption is generated in the operation of the carburetor There is this.

On the other hand, Republic of Korea Patent No. 10-0981398 "Logistics warehouse cooling system using the LNG gas liquefied heat" (2010.9.3 registered) has been proposed, the prior art is the heat of vaporization generated from LNG liquefied gas, cooling the warehouse It is proposed that it can be used as a cold heat source. However, the prior art can be applied only to an area requiring a large amount of LNG (specifically, NG gas, which is a meteorological LNG), difficult to be introduced in an area requiring a small amount of LNG, and also a system using a liquid LNG by vaporizing basically. to be.

The present invention has been made in order to solve the problems of the prior art as described above, and supplies a small amount of LENG to the meteorological LENG demand through the meteorological LENG demand supply line, at this time, to supply a sufficient amount of meteorological LENG within the LNG storage tank. In order to ensure that the liquid LNG discharges the cold heat through the load heat exchanger of the cold storage supply for the warehouse and thereby the temperature of the liquid LENG is raised or vaporized, and thus the elevated temperature or vaporized LENG is supplied to the meteorological LGE It is aimed to be able to supply to, and to expand the use and dissemination of cold heat of LENG.

In another aspect, the present invention is to provide a LNG optimum control reliquefaction system to recover the low temperature waste heat of LNG generated during the LNG vaporization process.

In order to solve the above problems, the present invention, the LENG storage tank in which the LENG is stored; A meteorological LNG discharge line having one end connected to the LNG storage tank and configured to discharge a vapor phase LNG from the LNG storage tank; The first-first heat medium passing through the first-first heat medium flow path and the first-second heat medium passing through the 1-2th heat medium flow path are formed to heat exchange with each other, and one end of the first-first heat medium flow path is the gas phase EL engine. A heat exchanger for condensation connected to the other end of the discharge line; A gas phase LCD customer demand supply line, one end of which is connected to the other end of the first-first heat medium flow path of the heat exchanger for condensation, and a plurality of gaseous LGE demand destinations connected to the other end; A liquid LNG discharge line having one end connected to the LNG storage tank and provided to discharge the liquid LNG from the LENG storage tank; A cold storage supply unit for the warehouse configured to absorb cold heat of the liquid LNG by providing at least one load heat exchanger to the other end of the liquid LENG discharge line and supply the cold heat to the distribution warehouse; An elevated LNG flow line provided with an LNG in which cold heat is absorbed by the load heat exchanger of the cold warehouse supply unit for the warehouse; A reliquefaction device provided to cool the temperature rising LG engine past the temperature rising LG engine flow line; A cooler for a reliquefaction machine configured to supply cold heat for cooling the reliquefaction liquid; An L engine return line for a reliquefaction machine, which is connected to the reliquefaction machine and the LNG storage tank and is provided to return the LNG passing through the reliquefaction machine to the LNG storage tank; A second-first end connected to the gas phase EL discharge line, a second-second end connected to the other end of the first-first heat medium flow path of the heat exchanger for condensation, and a second second connected to the reliquefaction machine A gas phase LCD return line having three ends, wherein the second-first end, the second-second end, and the second-three end communicate with each other; A high temperature cooling tank in which high temperature cooling water is stored; A low temperature cooling tank in which low temperature cooling water is stored; An auxiliary cold heat supply unit configured to supply auxiliary cooling heat to the cold heat supply unit for the warehouse using the low temperature cooling water of the low temperature cooling tank as the condensation heat source, and to supply the low temperature cooling water to the high temperature cooling tank; A cooling water circulation pipe for a storage tank provided to transfer the high temperature cooling water of the high temperature cooling tank to the low temperature cooling tank; A power generation evaporator configured to evaporate and expand the power generation refrigerant by the high temperature cooling water passing through the storage tank cooling water circulation pipe; The refrigerant for power generation is condensed while passing through the 1-2 heat medium flow path, and the power generation refrigerant is flowed through the 1-2 heat medium flow path of the heat exchanger for condensation so as to evaporate and expand through the power generation evaporator. Refrigerant circulation pipe for power generation provided to circulate the evaporator for; A power generation refrigerant circulation pump provided in the power generation refrigerant circulation pipe; A turbine generator provided in the power generation refrigerant circulation pipe between the rear end of the power generation evaporator and the front end of the heat exchanger for condensation and generated by the power generation refrigerant; A first control valve provided between the gas phase EL engine discharge line and the first-first heat medium flow path of the heat exchanger for condensation; A second control valve provided between the gaseous LENG discharge line and the gaseous LENG return line; A third control valve disposed between the first-first heat medium flow path of the heat exchanger for condensation and the supply line to the gas phase EL engine; A fourth control valve provided between the first-first heat medium flow path of the heat exchanger for condensation and the gas phase EL return line; Characterized in that comprises a.

In the above: the coolant for the reliquefaction liquid is controlled to supply or not supply cold heat to the reliquefaction liquid; The liquid LENG flows through the liquid LENG discharge line, the load heat exchanger for the cold heat supply unit of the warehouse, the temperature rising L flow line, the reliquefaction machine, the L liquid return line for the reliquefaction unit, the reliquefaction of the cooler May stop running and not cool down past the reliquefaction machine; Preferably, the first, second, third, and fourth control valves are controlled to be opened and closed according to the flow rate of the gaseous-phase engine, supplied to the demand for the gas-phase engine, and whether or not the turbine generator is driven, and the pressure of the engine storage tank.

As described above, the present invention is to supply a small amount of LNG to the meteorological LENG demand through the supply line of the meteorological LENG demand, in this case, in order to be able to supply a sufficient amount of the LNG in the LNG storage tank liquid LNG cold warehouse for the warehouse The cooling heat is discharged through the load heat exchanger of the supply unit so that the temperature of the liquid LENG is elevated or vaporized, and thus the elevated or vaporized LEN can be supplied to the supply line of the LNG LG. It is possible to expand the supply.

In addition, the present invention is to economically recover the low-temperature waste heat of LNG generated during the LNG vaporization process by the optimum controlled reliquefaction of the flow rate of the liquid and gaseous LENG.

1 is a schematic diagram of an LNG optimum control reliquefaction system for LNG low temperature waste heat recovery generated during the LNG vaporization process according to an embodiment of the present invention,

2 to 5 are flowcharts for explaining the operating state of the present system.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted for simplicity of explanation, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, without excluding other components unless specifically stated otherwise.

Specific types of the coolant above and below are just one embodiment, and various types of coolant may be applied according to the embodiment.

Pipe or line in the present embodiment means a pipe line for guiding the flow of the fluid, pumps, valves and the like provided in the pipe or line should be understood as part of the pipe without any description.

In the above and hereinafter, LENG is defined as the LGE of the gas phase and liquid LENG, and gaseous LENG such as BOG or NG gas is referred to as gaseous LENG, and liquid LENG or liquefied LENG is called liquid LENG do.

1 is a schematic diagram of an LNG optimum control reliquefaction system for LNG low temperature waste heat recovery generated during the LNG vaporization process according to an embodiment of the present invention.

The LNG storage tank 100 stores the LENG. In this embodiment, the LNG is transported using the tank lorry to fill the LNG in the LNG storage tank 100.

In the lower part of the L engine storage tank 100, the L engine is stored in a liquid state of about -160 ~ -130 ℃.

The inner upper portion of the LNG storage tank 100 is filled with a gaseous LNG such as BOG gas.

The gaseous LENG and the liquid LNG may be discharged from the LNG storage tank 100 as described above.

The gaseous LNG discharge line 110 is provided to discharge the gaseous LNG from the LNG storage tank 100.

One end of the meteorological LNG discharge line 110 is connected to the LNG storage tank 100 so that the weather LNG is discharged from the LNG storage tank 110.

In addition, the liquid LENG discharge line 160 is provided to discharge the liquid LEN from the LNG storage tank 100.

Liquid LENG discharge line 160 is one end is connected to the LENG storage tank 100 is provided so that the liquid LENG is discharged from the LENG storage tank (100).

The first load heat exchanger 201 and the second load heat exchanger 202 of the warehouse cold heat supply unit 200 are sequentially provided at the other ends of the liquid LENG discharge line 160.

The first load heat exchanger 201 and the second load heat exchanger 202 absorb cold heat of the liquid LENG, and the cold heat supply unit 200 for the warehouse is provided to supply the absorbed cold heat to the warehouse. .

The cold heat supply unit 200 for the distribution warehouse will be described later.

Therefore, the liquid phase L cells passing through the first and second

load heat exchangers

201 and 202 may be cooled by releasing cold heat, and some or all of them may be vaporized.

The rear end of the first and second load heat exchangers (201, 202) is provided with a temperature increase L-engine flow line 170 is provided by the heat exchangers (201, 202) of the load of the cold heat supply unit 200 for the warehouse warehouse to absorb the cold heat Guide the LNG to flow to the reliquefaction unit 180.

The reliquefaction unit 180 is provided at the rear end of the temperature rising LNG flow line 170.

The reliquefaction unit 180 is provided to cool the temperature rising LG engine past the temperature rising LG engine flow line 170 to liquefy the gas phase EL or to cool the high temperature liquid EL to the low temperature liquid EL. However, as described below, the operating time of the reliquefaction machine 180 should be minimized in the control method of the present embodiment.

In other words, the reliquefaction unit 180 cools the gas phase L / G or the high temperature liquid LG, thereby liquefying the gas phase L / L into the liquid LG, or cools the high temperature liquid LG to the low temperature liquid LJ.

In order to supply cooling heat for cooling to the reliquefaction unit 180, a reliquefaction cooler 181 is provided.

The reliquefaction cooler 181 may be integrated with the reliquefaction unit 180 or may be provided separately from the reliquefaction unit 180.

The L ENG cooled in the reliquefaction unit 180 is returned to the L ENG storage tank 100 by the L ENG return line 190 for the reliquefaction unit. That is, the L NG return line 190 for the reliquefaction unit is provided to connect the reliquefaction unit 180 and the L ENG storage tank 100.

As described above, the liquid LENG is the liquid LENG discharge line 160, the first and second load heat exchangers (201, 202) of the cold heat supply unit 200 for the warehouse, the temperature rise LENG flow line 170, the reliquefaction unit 180, ash It flows along the LENG return line 190 for the liquefier.

At this time, the system basically stops driving of the reliquefaction cooler 181, so that the LNG is passed through the reliquefaction unit 180 and is driven in a gaseous phase LG generation mode in which the LNG is not cooled. That is, in this system, the operation of the reliquefaction unit 180 is stopped, so that the liquid LENG discharges cold heat to the first and second

load heat exchangers

201 and 202 of the cold heat supply unit 200 for the warehouse and converts it to a gas phase LNC. Mode.

That is, the system is driven in a manner that the driving of the reliquefaction cooler 181 is controlled.

Of course, the coolant 181 for the reliquefaction machine in the present embodiment is controlled to operate when the pressure of the LENG storage tank 100 is excessively increased to supply cold heat.

As described above, the coolant 181 and the reliquefaction device 180 for the reliquefaction apparatus are selectively controlled not to supply or supply cold heat to the circulation pipe of the liquid LENG.

On the other hand, the other end of the gas phase LG discharge line 110 is connected to the heat exchanger for condensation 120 and the gas phase LG return line 140, respectively.

The heat exchanger 120 for condensation is performed such that the first-first heat medium passing through the first-first heat medium flow path and the first-second heat medium passing through the 1-2th heat medium flow path exchange heat with each other, and the first-first heat medium. One end of the flow path is connected to the other end of the gas phase LG discharge line 110.

Therefore, the gaseous L / N passing through the gaseous L / N discharge line 110 flows in the 1-1 heat medium flow path of the heat exchanger 120 for condensation. In addition, the gas phase L engine flowing through the 1-1 heat medium flow path of the heat exchanger 120 for condensation is heated to a temperature required for use by heat exchange with the 1-2 heat medium flowing through the 1-2 heat medium flow path.

In addition, the gas phase L engine return line 140 is connected to the second end of the first and second heat medium flow path of the heat exchanger 120 for condensation, and the second end of the first and second heat exchanger 120, 2- It has a second end and a 2-3 end connected to the reliquefaction unit 180, the second-first end, the second-second end and the second-end end is made to communicate with each other.

Therefore, the gaseous LNG return line 140 is the gaseous LENG discharge line 110 or the gaseous LNG flows from the 1-1 heat medium flow path of the heat exchanger 120 for condensation flows out to the reliquefaction unit 180.

That is, the weather LNG return line 140, by sending the weather LENG to the reliquefaction unit 180 to liquefy the weather LENG, but if the pressure of the LENG storage tank 100 excessively liquefied a part of the weather LENG. To be used.

In addition, the other end of the first-first heat medium flow path of the heat exchanger 120 for condensation is connected to the second-second end of the gas phase L / N return line 140, and also supplies the gaseous LNG demand source connected to a plurality of gaseous LNG demand destinations. Line 130 is connected.

The meteorological LNG demand source supply line 130 is provided to supply the meteorological LNG to the demand destination.

The meteorological LNG demand source supply line 130 is provided with a plurality of proportional control valves 130-1, 2, 3, 4, 5, 6, and 7 for supplying the meteorological LNG to each demand destination in a proportional control manner.

In addition, as a demand source for the weather LENG, 1) defrosting water generation (131-1) for removing defrosting of the evaporator provided in the frozen or refrigerated distribution warehouse, 2) heat source (131-2), 3 for hot water supply, hot water, etc. of the factory ) Heat source (131-3) of gas heat pump (GHP) located in offices and laboratories, 4) Emergency generator operation in logistics center (131-4), 5) City gas piping (131-5), 6) Logistics center The plant 131-6, 7) for fuel 131-7, etc. of the fuel cell may be exemplified.

Meanwhile, a first control valve 111 is provided between the gaseous LNG discharge line 110 and the first-first heat medium flow path of the heat exchanger 120 for condensation, and the gaseous LNG discharge line 110 and the gaseous LNG return line ( A second control valve 112 is provided between the first and second control valves 112, and a third control valve 113 is provided between the first-first heat medium flow path of the condensation heat exchanger 120 and the gaseous supply and demand destination line 130. A fourth control valve 114 is provided between the first-first heat medium flow path of the heat exchanger 120 for condensation and the gas phase L engine return line 140.

The first, second, third, and

fourth control valves

111, 112, 113, and 114 are controlled to open and close according to the flow rate of the gaseous-phase engine, supplied to the demand for the gas-phase engine, whether or not the turbine generator is to be described later, and the pressure of the engine storage tank. .

Hereinafter, a description will be given of the cold storage supply unit for the warehouse warehouse for supplying cold heat to the various warehouses, including the refrigerated warehouse.

The first load heat exchanger 201 discharges the cold heat while the temperature of the -Engine at about -160 ° C is raised to about -100 ° C, and the second load heat exchanger 202 has the -100 ° C at about -60 ° C. As the temperature rises, the cold heat is discharged.

As described above, a first refrigerant circulation pipe is provided in order to exchange heat with the L & G passing through the first load heat exchanger 201 to transmit cold heat to the warehouse.

The first refrigerant circulation pipe includes a first load heat exchanger 201, a first refrigerant storage tank 211, a first refrigerant circulation pump 212, a 1-1 heat exchanger 213, and a first load. A pipe circulating through the heat exchanger 201 is formed.

In the present embodiment, the first refrigerant is propane (R-290), and the temperature of the first refrigerant immediately before flowing into the first load heat exchanger 201 is -70 ° C, and from the first load heat exchanger 201. Immediately after the outflow, the temperature of the first refrigerant is -80 ° C. That is, the temperature of the first refrigerant immediately before flowing into the 1-1 heat exchanger 213 is -80 ° C, and the temperature of the first refrigerant immediately after flowing out of the 1-1 heat exchanger 213 is -70 ° C. It is the same meaning.

Such a first refrigerant is provided to extract the coldest cold heat from LENG.

The first auxiliary refrigerant circulation pipe is connected to the first refrigerant circulation pipe via the first-first heat exchanger 213.

The first auxiliary refrigerant circulation pipe includes the first-first heat exchanger 213, the first auxiliary refrigerant storage tank 221, the first auxiliary refrigerant circulation pump 222, the first unit cooler 223, and the first. A pipe circulating through the -1 heat exchanger 213 is formed.

In the present embodiment, the first auxiliary refrigerant may be R-407c, R-507a, or the like as a secondary refrigerant, and the temperature of the first auxiliary refrigerant immediately before flowing into the 1-1 heat exchanger 213 is -65 ° C. The temperature of the first auxiliary refrigerant immediately after flowing out of the 1-1 heat exchanger 213 is -75 ° C. This means that the temperature of the first auxiliary coolant immediately before flowing into the first unit cooler 223 is -75 ° C, and the temperature of the first auxiliary coolant immediately after flowing out of the first unit cooler 223 is -65 ° C. .

The first unit cooler 223 is used as a load of the first auxiliary refrigerant for cooling the inside of the warehouse and is a kind of cold load.

That is, the plurality of first unit coolers 223 may supply cooling heat to an ice cream storage warehouse, an F-class refrigerator, an SF-class refrigerator (for ultra low temperature), a processing plant refrigerator, a cryogenic laboratory, and the like in a warehouse.

As described above, the first refrigerant circulation pipe delivers the coolest cold heat to the warehouse through the first auxiliary refrigerant circulation pipe.

A second refrigerant circulation pipe is provided to exchange heat with the L & G passing through the second load heat exchanger 202 to transfer the cold heat to the warehouse.

The second refrigerant circulation pipe includes a second load heat exchanger 202, a second refrigerant storage tank 231, a second refrigerant circulation pump 232, a second unit cooler 233, and a second load heat exchanger. A pipe circulating the machine 202 is formed.

In the present embodiment, the second refrigerant may be carbon dioxide (CO2), R-407c, R-507a, or the like, and the temperature of the second refrigerant immediately before flowing into the second load heat exchanger 202 is -10 ° C. The temperature of the second refrigerant immediately after flowing out from the second load heat exchanger 202 is -15 ° C. That is, the temperature of the second refrigerant immediately before flowing into the second unit cooler 233 is −15 ° C., and the temperature of the second refrigerant immediately after flowing out of the second unit cooler 233 is −10 ° C.

The second unit cooler 233 is used as a load of the first auxiliary refrigerant for cooling the inside of the warehouse and is a kind of cold load, and the plurality of second unit coolers 233 are used for storing documents and processing in the warehouse. Cold air can be supplied to the air conditioning of the factory, C2 refrigerators.

As described above, the second refrigerant circulation pipe directly transmits cold heat to the warehouse.

Meanwhile, in order to operate the system more economically, the cooling water storage tank 450 and the auxiliary cooling heat supply unit 400 are provided.

The cooling water storage tank 450 includes a low temperature cooling tank 451 in which low temperature cooling water is stored, and a high temperature cooling tank 452 in which high temperature cooling water is stored.

The auxiliary cold heat supply unit 400 supplies the auxiliary cold heat to the cold heat supply unit 200 for the warehouse using the low temperature cooling water of the low temperature cooling tank 451 as the condensation heat source, and the low temperature cooling water used as the condensation heat source is high temperature. It is made to convey to the cooling tank 452.

As the auxiliary cooling heat supply unit 400, the 1-2 coolant circulation unit, the first coolant circulation unit, the 2-2 refrigerant circulation unit and the second coolant circulation unit are respectively provided.

The 1-2 refrigerant circulation section includes the 1-2 refrigerant storage tank 411, the 1-2 refrigerant circulation pipe 412, and the first unit cooler 223.

The 1-2 refrigerant is stored in the 1-2 refrigerant storage tank 411.

In order to supply and recover the 1-2 refrigerant stored in the 1-2 refrigerant storage tank 411, the 1-2 refrigerant circulation pipe 412 is provided, and the 1-2 refrigerant circulation pipe 412 is provided with logistics. The first unit cooler 223 is connected as a load of the first refrigerant for cooling the inside of the warehouse.

That is, the first unit cooler 223 may be connected to the first-second refrigerant circulation part and also connected to the first auxiliary refrigerant circulation pipe to supply the first-second refrigerant or the first auxiliary refrigerant.

A first coolant circulation part is provided to cool the 1-2 refrigerant used as the refrigerant of the 1-2 refrigerant circulation part.

The first cooling water circulation unit includes a first water cooling refrigerator 431, a first cooling water circulation pipe 432, and a cooling water storage tank 450.

The first water-cooled refrigerator 431 receives the 1-2 refrigerant stored in the 1-2 refrigerant storage tank 411, cools it, and returns the same to the 1-2 refrigerant storage tank 411.

The first water-cooled refrigerator 431 performs the compression and condensation process for the 1-2 refrigerant, and in particular, the cooling water is used as the condensation heat source. That is, the first water-cooled refrigerator 431 needs to continuously supply cooling water for compression and condensation of the refrigerant, particularly for condensation.

The first cooling water circulation pipe 432 is provided to supply the cooling water to be used as the condensation heat source of the first water cooling refrigerator 431 and to recover the cooling water used as the condensation heat source to the cooling water storage tank 450.

The first water-cooled refrigerator 431 uses the cooling water of the low temperature cooling tank 451 and then conveys it to the high temperature cooling tank 452.

The second-second refrigerant circulation unit includes a second-second refrigerant storage tank 421, a second-second refrigerant circulation pipe 422, and a second unit cooler 233.

The second-2 refrigerant is stored in the second-2 refrigerant storage tank 421.

In order to supply and recover the second-two refrigerant stored in the second-two refrigerant storage tank 421, a second-two refrigerant circulation pipe 422 is provided, and the second-two refrigerant circulation pipe 422 is provided with logistics. The second unit cooler 233 is connected as a load of the second-two refrigerant for cooling the inside of the warehouse.

A second coolant circulation part is provided to cool the second-2 refrigerant used as the refrigerant of the second-2 refrigerant circulation part.

The second cooling water circulation unit includes a second water cooling refrigerator 441, a second cooling water circulation pipe 442, and a cooling water storage tank 450.

The second water-cooled refrigerator 441 receives the second-two refrigerant stored in the second-two refrigerant storage tank 421, cools it, and returns the same to the second-two refrigerant storage tank 421.

The second water-cooled refrigerator 441 performs the compression and condensation process for the second-two refrigerants, and in particular, the cooling water is used as the condensation heat source. That is, the second water-cooled refrigerator 441 needs to continuously supply cooling water.

The second cooling water circulation pipe 442 is provided to supply the cooling water to be used as the condensation heat source of the second water cooling refrigerator 441 and to recover the cooling water used as the condensation heat source to the cooling water storage tank 450.

That is, the 2nd water-cooled refrigerator 441 uses the cooling water of the low temperature cooling tank 451, and returns to the high temperature cooling tank 452. FIG.

Meanwhile, the first water-cooled refrigerator 431 receives the first refrigerant stored in the first refrigerant storage tank 211, cools the first refrigerant, and then returns the refrigerant to the first refrigerant storage tank 211. ) Is prepared.

In addition, the second water-cooled refrigerator 441 receives a second refrigerant stored in the second refrigerant storage tank 231, cools the second refrigerant, and then returns the refrigerant to the second refrigerant storage tank 231 to return the refrigerant to the second refrigerant storage tank 231. ) Is prepared.

Meanwhile, the cooling water storage tank 450 is provided with a cooling water circulation pipe 453 for the storage tank.

The storage tank cooling water circulation pipe 453 is provided to transfer the high temperature cooling water of the high temperature cooling tank 452 to the low temperature cooling tank 451.

In addition, a power generation evaporator 320 configured to evaporate and expand the power generation refrigerant by the high temperature cooling water passing through the storage tank cooling water circulation pipe 453 is provided.

Therefore, the cooling water circulation pipe 453 for the storage tank supplies the high temperature cooling water of the high temperature cooling tank 452 to the power generation evaporator 320 to use the evaporation heat source, and uses the coolant cooled while passing through the power generation evaporator 320. The low temperature cooling tank 451 is recovered.

The refrigerant for power generation is condensed while passing through the 1-2 heat medium flow path of the heat exchanger 120 for condensation, and the refrigerant for power generation is evaporated and expanded through the evaporator 320 for power generation. A power generation refrigerant circulation pipe 330 is provided to circulate the 1-2 heat medium flow path and the power generation evaporator 320.

The power generation refrigerant circulation pipe 330 is provided with a power generation refrigerant circulation pump 331 for circulating the power generation refrigerant.

In addition, a turbine generator 310 is provided in the power generation refrigerant circulation pipe 330 between the rear end of the power generation evaporator 320 and the front end of the condensation heat exchanger 120, and the turbine generator 310 is formed by a power generation refrigerant. Generate power.

As a result, the power generation refrigerant circulation pipe 330 is a power generation refrigerant condensation heat exchanger 120, power generation refrigerant circulation pump 331, power generation evaporator 320, turbine generator 310, heat exchanger for condensation It is formed to circulate 120.

In addition, the refrigerant for power generation is condensed using the gaseous phase L engine as a condensation heat source in the heat exchanger 120 for condensation, and the refrigerant for power generation evaporates the high temperature cooling water passing through the cooling water circulation pipe 453 for the storage tank in the power generation evaporator 320. Evaporated using the heat source, the refrigerant evaporated and expanded in this way is to rotate the turbine generator 310 while passing through the turbine generator 310 to produce power.

In addition, the heat exchanger 120 for condensation raises the temperature of the gas phase LN to a temperature suitable for the demand, and the power generation evaporator 320 converts the high temperature cooling water of the high temperature cooling tank 452 into low temperature cooling water.

Meanwhile, in the present embodiment, the Stirling cooler 181 is adopted as the coolant 181 for the reliquefaction machine provided to supply cold heat to the reliquefaction machine 180.

The Stirling cooler uses a thermodynamic property that releases and absorbs heat from the gas to the surroundings during the compression or expansion of the ideal gas (usually using H or He). It is a device for pumping heat into a furnace.

The heat pipe 182 is provided to receive the cold heat generated in the Stirling Cooler 181, that is, the cold heat from the low temperature part of the Stirling Cooler 181, and deliver it to the reliquefaction unit 180.

That is, one end of the heat pipe 182 is arranged to receive the cold heat from the low temperature part of the Stirling cooler 181, and supplies the cold heat for liquefaction to the reliquefaction unit 180 at the other end. Such an arrangement allows the cooling heat to be transmitted only by the arrangement of the heat pipes without using the refrigerant, thereby simplifying the structure.

The sterling cooler 181 supplies cold heat at the low temperature portion (that is, absorbs heat) during the cooling process and releases heat to the outside at the high temperature portion. In this way, by using the waste heat (181a) emitted to the outside in the cooling process can be used as an evaporation heat source of the power generation evaporator 320 can be produced additional power.

As the reliquefaction cooler 181, a multistage or turbo compression expansion cryogenic freezer may be utilized depending on the embodiment, and a helium, hydrogen, nitrogen, oxygen, hydrocarbon refrigerant, or the like may be adopted as the refrigerant.

The operation of the present system as described above will be described.

2 to 5 are flowcharts for explaining an operating state of the present system.

2 to 5 illustrate the flow of the liquid and gaseous LENG.

In FIG. 2, only the liquid LENG is discharged and flows, and the gaseous LEN is not discharged. Therefore, the first, second, third and

fourth control valves

111, 112, 113 and 114 are all closed.

In FIG. 2, the LNG storage tank 100 functions as a buffer tank for storing the gaseous LNG in which the liquid LNG is converted. That is, the reliquefaction unit 180 is not operated, and the liquid LENG is converted into the gas phase LEN.

This can be seen as a step to prepare enough to discharge the weather LENG at any time.

However, when the pressure of the LNG storage tank 100 rises excessively, the reliquefaction cooler 181 is operated.

3 illustrates that both the liquid LG and the gaseous LGE are discharged, the second and

fourth control valves

112 and 114 are closed, and the first and third control valves 111 and 113 are open.

In addition, in FIG. 3, the reliquefaction unit 180 is basically not operated.

Therefore, the liquid LENG is vaporized while passing through the

load heat exchangers

201 and 202, and a large amount of gaseous LNG generated by the vaporization is discharged and heated up through the heat exchanger 120 for condensation. 130 is supplied to each source.

In this state, the amount of liquid LNG is converted to the gaseous LENG, and the amount of the gaseous LGE discharged is the most desirable state, and most of the operation is performed alternately the state of FIG. 2 and FIG.

4 illustrates that both the liquid LG and the gaseous LGE are discharged, the fourth control valve 114 is closed, and the first, second, and

third control valves

111, 112, and 113 are open.

Therefore, the liquid LENG is vaporized while passing through the

load heat exchangers

201 and 202, while a large amount of gaseous LNG generated by the vaporization is discharged while a part of the gaseous LNG is heated while passing through the heat exchanger 120 for condensation. While it is supplied to each customer through the LENG demand source supply line 130, a part of the weather LNG is transferred to the reliquefaction unit 180 to be liquefied.

In this case, the first and second control valves 111 and 112 may be proportionally controlled.

5 shows that both the liquid and gaseous LNG are discharged, the second and

third control valves

112 and 113 are in a closed state, and the first and fourth control valves 111 and 114 are in an open state.

Accordingly, the liquid LENG is vaporized while passing through the

heat exchangers

201 and 202 for load, and a large amount of gaseous LNG generated by the vaporization is discharged from the LNG storage tank 110, and the gaseous LNG is used to discharge the heat exchanger 120 for condensation. After the temperature rises, the liquid is transferred to the reliquefaction unit 180 to be reliquefaction.

This shows when the weather LENG is generating power to the turbine generator 310 without the need to be supplied to the weather LENG demand.

As described above, the system heats the gaseous phase L engine through the heat exchanger 120 for condensation and supplies it to various gas phase LG energy demand destinations. The LG discharges the cold heat through the first and second

load heat exchangers

201 and 202 of the cold storage supply part of the warehouse, thereby allowing the temperature of the liquid LG to be raised or vaporized, so that a sufficient amount of the gaseous LNG is required for the gas phase LGE demand. To be supplied.

In addition, the cold storage supply unit for the warehouse 200 can supply the cold heat to the warehouse by using the cold heat generated by the vaporization of the liquid L ENG, it can operate a refrigerated frozen warehouse, and also the cold heat generated during the temperature rising process of the weather L ENG Optimized energy recovery is achieved by generating power from the turbine generator using high-temperature coolant from the and sub-cooling supplies.

Such a system will expand the spread of LNG by constructing LNG storage tanks of sufficient size in each region, discharging a small amount of gas LNG from the demand, and actively utilizing the full cooling and cooling of liquid LNG. Renewable energy can be used most efficiently.

The foregoing description of the present invention is intended for illustration, and it will be understood by those skilled in the art that the present invention may be easily modified in other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, the embodiments described above are to be understood in all respects as illustrative and not restrictive. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined form.

The scope of the present invention is shown by the following claims rather than the above description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention. do.

The present invention can be used to recover the LNG low temperature waste heat generated during the LNG vaporization process.

Claims

LNG storage tank where LNG is stored;

A meteorological LNG discharge line having one end connected to the LNG storage tank and configured to discharge a vapor phase LNG from the LNG storage tank;

The first-first heat medium passing through the first-first heat medium flow path and the first-second heat medium passing through the 1-2th heat medium flow path are formed to heat exchange with each other, and one end of the first-first heat medium flow path is the gas phase EL engine. A heat exchanger for condensation connected to the other end of the discharge line;

A gas phase LCD customer demand supply line, one end of which is connected to the other end of the first-first heat medium flow path of the heat exchanger for condensation, and a plurality of gaseous LGE demand destinations connected to the other end;

A liquid LNG discharge line having one end connected to the LNG storage tank and provided to discharge the liquid LNG from the LENG storage tank;

A cold storage supply unit for the warehouse configured to absorb cold heat of the liquid LNG by providing at least one load heat exchanger to the other end of the liquid LENG discharge line and supply the cold heat to the distribution warehouse;

An elevated LNG flow line provided with an LNG in which cold heat is absorbed by the load heat exchanger of the cold warehouse supply unit for the warehouse;

A reliquefaction device provided to cool the temperature rising LG engine past the temperature rising LG engine flow line;

A cooler for a reliquefaction machine configured to supply cold heat for cooling the reliquefaction liquid;

An L engine return line for a reliquefaction machine, which is connected to the reliquefaction machine and the LNG storage tank and is provided to return the LNG passing through the reliquefaction machine to the LNG storage tank;

A second-first end connected to the gas phase EL discharge line, a second-second end connected to the other end of the first-first heat medium flow path of the heat exchanger for condensation, and a second second connected to the reliquefaction machine A gas phase LCD return line having three ends, wherein the second-first end, the second-second end, and the second-three end communicate with each other;

A high temperature cooling tank in which high temperature cooling water is stored;

A low temperature cooling tank in which low temperature cooling water is stored;

An auxiliary cold heat supply unit configured to supply auxiliary cooling heat to the cold heat supply unit for the warehouse using the low temperature cooling water of the low temperature cooling tank as the condensation heat source, and to supply the low temperature cooling water to the high temperature cooling tank;

A cooling water circulation pipe for a storage tank provided to transfer the high temperature cooling water of the high temperature cooling tank to the low temperature cooling tank;

A power generation evaporator configured to evaporate and expand the power generation refrigerant by the high temperature cooling water passing through the storage tank cooling water circulation pipe;

The refrigerant for power generation is condensed while passing through the 1-2 heat medium flow path, and the power generation refrigerant is flowed through the 1-2 heat medium flow path of the heat exchanger for condensation so as to evaporate and expand through the power generation evaporator. Refrigerant circulation pipe for power generation provided to circulate the evaporator for;

A power generation refrigerant circulation pump provided in the power generation refrigerant circulation pipe;

A turbine generator provided in the power generation refrigerant circulation pipe between the rear end of the power generation evaporator and the front end of the heat exchanger for condensation and generated by the power generation refrigerant;

A first control valve provided between the gas phase EL engine discharge line and the first-first heat medium flow path of the heat exchanger for condensation;

A second control valve provided between the gaseous LENG discharge line and the gaseous LENG return line;

A third control valve disposed between the first-first heat medium flow path of the heat exchanger for condensation and the supply line to the gas phase EL engine;

A fourth control valve provided between the first-first heat medium flow path of the heat exchanger for condensation and the gas phase EL return line;

LNG optimum control reliquefaction system for LNG low temperature waste heat recovery generated during the LNG vaporization process comprising a.
According to claim 1:

The coolant for the reliquefaction liquid is controlled to supply or not supply cold heat to the reliquefaction liquid;

The liquid LENG flows through the liquid LENG discharge line, the load heat exchanger for the cold heat supply unit of the warehouse, the temperature rising L flow line, the reliquefaction machine, the L liquid return line for the reliquefaction unit, the reliquefaction of the cooler May stop running and not cool down past the reliquefaction machine;

The first, second, third, and fourth control valves of the LNG vaporization, characterized in that the opening and closing is controlled in accordance with the flow rate of the gaseous LENG supplied to the demand for the gaseous LENG, the driving of the turbine generator, the pressure of the LNG storage tank. LNG optimal control reliquefaction system for recovery of LNG low temperature waste heat generated during the process.