KR102528543B1 - Liquefied gas regasification system - Google Patents

Abstract

A liquefied gas regasification system according to the present invention includes a storage tank for storing liquefied gas; a fuel gas supply line connecting the storage tank and a consumer; A boil-off gas line for re-liquefying the BOG stored in the storage tank using a recondenser and then sending it to the fuel gas supply line; and an ejector supply line branched off from the fuel gas supply line and connected to the consumer.

Description

Liquefied gas regasification system {LIQUEFIED GAS REGASIFICATION SYSTEM}

The present invention relates to a liquefied gas regasification system.

In general, LNG is known to be a clean fuel and its reserves are richer than petroleum, and its use is rapidly increasing as mining and transportation technologies develop. It is common for LNG to store methane, the main component, in a liquid state by lowering the temperature to -162 ° C or lower under 1 atm. is 0.42, which is about 1/2 of the specific gravity of crude oil.

LNG is liquefied for ease of transportation and then vaporized at the place of use after transportation. On the other hand, installing LNG vaporization facilities on land accompanies various risks such as natural disasters and terrorism. For this reason, instead of the existing liquefied natural gas regasification system installed on land, a facility to supply vaporized natural gas to land by installing a regasification device on an LNG carrier carrying liquefied natural gas. is in the limelight.

0001) Korean Registered Patent No. 10-1767558 (Announced on August 11, 2017)

An object of the present invention is to provide a liquefied gas regasification system that efficiently re-liquefies and manages boil-off gas present in a storage tank.

According to one aspect of the present invention, a storage tank in which liquefied gas is stored; a fuel gas supply line connecting the storage tank and a consumer; A boil-off gas line for re-liquefying the BOG stored in the storage tank using a recondenser and then sending it to the fuel gas supply line; A liquefied gas regasification system including an ejector supply line branched from the fuel gas supply line and connected to the consumer, sucking in the BOG stored in the storage tank and having an ejector for sending fuel gas toward the consumer. can

The ejector is provided in a first ejector supply line branched from the fuel gas supply line, and the first ejector mixes the passing liquefied gas with BOG and sends it toward the consumer; A second ejector provided in a second ejector supply line for sending the boil-off gas that has passed through the vaporizer in the fuel gas supply line toward the consumer, mixing BOG and sending it toward the consumer.

The consumer includes a first consumer connected to the fuel gas supply line; and a second consumer that requires fuel under a pressure condition or temperature condition different from that of the first consumer and is connected to the ejector supply line.

A heat exchanger may be provided in the ejector supply line between a rear end of the ejector and a second consumer.

An accumulator may be installed between the ejector and the heat exchanger in the ejector supply line.

The fuel gas supply line includes a supply pump for pumping liquefied gas in the storage tank; a high-pressure pump pressurizing liquefied gas to a pressure condition required by the first consumer; A vaporizer for vaporizing the liquefied gas passing through the fuel gas supply line; may be provided.

A cooling line for exchanging heat energy with a heat exchanger provided in the vaporizer or ejector supply line using seawater may be included.

The liquefied gas regasification system according to the present invention uses liquefied gas pressurized through a high-pressure pump as a driving fluid to inhale BOG generated in a storage tank without power and supply it to a demand place such as a power generation engine. Since a power generation engine can be driven without equipment such as a necessary expensive compressor, economic feasibility can be secured in system configuration.

In addition, by providing an ejector instead of a compressor for processing surplus BOG, construction costs can be reduced, power consumption can be reduced, and the failure rate is very low, resulting in improved driving reliability.

In addition, including a configuration related to the first ejector and the second ejector that utilizes different fluid flows as a driving fluid and an accumulator that mixes and supplies them to the engine, fuel is supplied to the second consumer on a limited basis only when fuel is needed. can supply

1 shows a liquefied gas regasification system according to a first embodiment of the present invention.
2 shows a liquefied gas regasification system according to a second embodiment of the present invention.
3 shows a liquefied gas regasification system according to a third embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments introduced below are provided as examples to sufficiently convey the spirit of the present invention to those skilled in the art. The present invention is not limited to the embodiments described below and may be embodied in other forms. In order to clearly explain the present invention, parts irrelevant to the description are omitted from the drawings, and in the drawings, the width, length, thickness, etc. of components may be exaggerated for convenience. Like reference numbers indicate like elements throughout the specification.

1 shows a liquefied gas regasification system according to a first embodiment of the present invention.

Referring to the drawings, a storage tank 10 in which liquefied gas is stored, fuel gas supply lines 201, 202, 203, 204 connecting the storage tank 10 and demand points 20 and 30, and the storage tank 10 After reliquefying the BOG stored in the BOG using the recondenser 42, the boil-off gas line 100 for sending it to the fuel gas supply lines (201, 202, 203, 204), sucking the BOG stored in the storage tank 10, and the demand place ( 20 and 30), a second ejector 60 is provided, and the ejector supply line 206 is branched from the fuel gas supply lines 201, 202, 203, and 204 and connected to the consumers 20 and 30. ).

The storage tank 10 stores liquefied gas to be supplied to the consumers 20 and 30. The liquefied gas storage tank 10 stores liquefied gas in a liquid state, and may be provided in the form of a pressure tank for this purpose. In this case, the liquefied gas may be liquefied natural gas (LNG), liquefied petroleum gas (LPG), or dimethyl ether (DME).

The storage tank 10 is a carrier that transports liquefied gas cargo such as an LNG carrier, an LNG RV (Regasification Vessel) carrier, an LPG carrier, or an ethylene carrier, or a Floating Storage Regasification Unit (FSRU) or a Floating Production Storage Offloading (FPSO) ), BMPP (Barge Mounted Power Plant), etc. can be applied to offshore floating facilities for storage and production of liquefied gas. Furthermore, the storage tank 10 may be applied not only to marine facilities but also to land facilities for storing liquefied gas.

The consumers 20 and 30 require a first consumer 20 connected to the fuel gas supply lines 201, 202, 203, and 204, and fuel under pressure conditions or temperature conditions different from those of the first consumer 20, It includes a second consumer 30 connected to the ejector supply line 206 .

The first demand point 20 may be an onshore terminal installed on land that vaporizes the liquefied gas vaporized in the vaporizer 83 to receive and use gaseous liquefied gas. In addition, the first consumer 20 may be an ME-GI engine requiring supply of fuel gas at a pressure of approximately 150 to 300 bar. In addition, the first consumer 20 may be a dual fuel engine capable of using not only NG but also heavy fuel oil (HFO) as a fuel.

The second consumer 30 may be an engine requiring fuel gas at a relatively low pressure compared to the first consumer 20 . For example, it may be a power generation engine such as a DFDE engine using a fuel gas of about 5 to 7 bar. At this time, like the first consumer 20, the second consumer 30 may also be a dual fuel engine using not only NG but also heavy fuel oil (HFO) as a fuel.

The boil-off gas line 100 may be a pipeline that transfers BOG from the storage tank 10 toward the recondenser 42 . The compressor 41 provided in the boil-off gas line 100 is a means for pressurizing the BOG in the storage tank 10, and may compress the BOG and send it to the recondenser 42. And the recondenser 42 is a means for re-liquefying the BOG in the storage tank 10, and mixes the liquefied gas supplied from the first fuel gas supply line 201 with BOG to form a second fuel gas supply line 202 can be sent to

The fuel gas supply lines 201, 202, 203, 204 connect the first fuel gas supply line 201 connecting the supply pump 43 and the recondenser 42, and the recondenser 42 and the vaporizer 83. And a fourth fuel gas supply line (connecting the second fuel gas supply line 202 and the third fuel gas supply line 203 where the high-pressure pump 44 is installed, and the vaporizer 83 and the first consumer 20) 204). At this time, a second control valve 204a is provided in the fourth fuel gas supply line 204 to control the flow rate flowing toward the first consumer 20 . In addition, the first fuel gas supply line 201 includes a return line 201a extending toward the storage tank 10 and a return valve 201b provided in the return line 201a, which is supplied toward the recondenser 42. The amount of liquefied gas can be adjusted.

In the fuel gas supply lines (201, 202, 203, 204), a supply pump 43 for pumping liquefied gas inside the storage tank 10 and a high pressure for pressurizing the liquefied gas under the pressure condition required by the first consumer 20 A vaporizer 83 for vaporizing liquefied gas passing through the pump 44 and the fuel gas supply lines 201, 202, 203, and 204 is provided.

The recovery line 205 is a pipeline that branches from the rear end of the recondenser 42 and extends toward the storage tank 10, and supplies the third fuel gas by controlling the first control valve 203a or the third control valve 205a. It may be provided to control the flow rate of the fuel gas supplied to the consumers 20 and 30 through the line 203.

The supply pump 43 is a means for sending the liquefied gas stored in the storage tank 10 toward the recondenser 42, and may be installed on the bottom of the storage tank 10. In addition, the high pressure pump 44 is a boosting pump provided in a line connected from the supply pump 43 to the first consumer 20 through the recondenser 42, and is required by the first consumer 20. Liquefied gas can be pressurized according to the pressure, and it can be composed of a centrifugal pump.

The vaporizer 83 is a means for vaporizing the liquefied gas flowing through the third fuel gas supply line 203, and may convert the liquefied gas into gaseous fuel gas using a heat exchange method.

The cooling line 300 includes a first cooling line 301 and a second cooling line 302 provided before and after the vaporizer 83, and a fresh water pump 81 is provided in the first cooling line 301 from the sea. By receiving seawater and supplying it to the vaporizer 83, the seawater is sent to the fuel gas through the vaporizer 83.

The first ejector supply line 206 is branched from the third fuel gas supply line 203 and extends toward the second consumer 30 . A first heat exchanger 82a is provided in the first ejector supply line 206 to adjust the supplied fuel gas to a temperature required by the second consumer 30 . The first ejector 50 is provided in the first ejector supply line 206 .

The first ejector 50 may play a role in converting the relatively high-pressure fuel gas into the low-pressure fuel gas required by the second consumer 30 . The high-pressure fuel gas is used as the driving force of the first ejector 50, but the low-pressure evaporation gas accommodated in the storage tank 10 is suctioned into the first suction gas line 101. , In the first ejector supply line 206, the high-pressure fuel gas and the boil-off gas are mixed with each other and discharged toward the second consumer 30. Here, the high-pressure fuel gas is at a pressure of approximately 15 to 17 bar, and the evaporated gas inside the storage tank 10 that is sucked may be approximately 0 to 1 bar.

2 shows a liquefied gas regasification system according to a second embodiment of the present invention. In the description of the liquefied gas regasification system according to the second embodiment of the present invention described below, the description of the name of the invention according to the first embodiment of the present invention described above and Descriptions are omitted to prevent duplication of content as the same.

Referring to the drawing, the second ejector supply line 207 is branched from the third fuel gas supply line 203 and extends toward the second consumer 30. A second heat exchanger 82b is provided in the first ejector supply line 206 to adjust the supplied fuel gas to a temperature required by the second consumer 30 . The second ejector 60 is provided in the second ejector supply line 207 .

The second ejector 60 may play a role in converting gaseous fuel gas in a relatively high pressure state into fuel gas in a low pressure state required by the second consumer 30 . The high-pressure fuel gas is used as the driving force of the second ejector 60, but the low-pressure evaporation gas accommodated in the storage tank 10 is suctioned into the second suction gas line 102. , In the second ejector supply line 207, the high-pressure fuel gas and the boil-off gas are mixed with each other and discharged toward the second consumer 30. That is, the second ejector 60 may combine the vaporized gas at the rear end of the vaporizer 83 and the gaseous boil-off gas supplied from the second suction gas line 102 to discharge gaseous fuel gas.

3 shows a liquefied gas regasification system according to a third embodiment of the present invention. In the description of the liquefied gas regasification system according to the third embodiment of the present invention described below, the liquefied gas regasification system according to the third embodiment of the present invention It is the same as the description for, and the description is omitted to prevent duplication of contents.

The boil-off gas line 100 may be a pipeline that transfers BOG from the storage tank 10 toward the recondenser 42 . Boil-off gas (BOG) flows in this boil-off gas line 100, and the branched first suction gas line 101 is connected to the first ejector 50 to provide BOG as a driving fluid, and the branched second The suction gas line 102 may be connected to the second ejector 60 to provide BOG as a driving fluid.

The ejector supply lines 206, 207, and 208 are branched from the third fuel gas supply line 203 and extend toward the accumulator 70, the first ejector supply line 206, the carburetor 83, the fourth fuel gas supply line 204 It includes a second ejector supply line 207 branched off from and extending toward the accumulator 70, and a third ejector supply line 208 extending from the accumulator 70 toward the second consumer 30. At this time, a fourth control valve 207a is provided in the second ejector supply line 207 to adjust the amount of gaseous fuel gas flowing toward the second ejector supply line 207 .

In the ejector supply lines 206 , 207 , and 208 , a heat exchanger 82 is provided between the rear end of each ejector 50 and 60 and the second consumer 30 . An accumulator 70 is installed between the ejectors 50 and 60 and the heat exchangers 82a and 82b.

The ejectors 50 and 60 are provided in the first ejector supply line 206 branched from the fuel gas supply lines 201, 202, 203, and 204, and mix the passing liquefied gas with the driving fluid so as to mix the fuel gas supply lines 201, 202, 203, and 204 with the demand points 20 and 30 ), the first ejector 50, and the second ejector supply line 207 for sending the boil-off gas from the fuel gas supply lines 201, 202, 203, 204 through the vaporizer 83 toward the consumers 20 and 30. ) It includes a second ejector 60 provided in.

The first ejector 50 may discharge gaseous fuel gas by combining liquid liquefied gas and gaseous evaporation gas supplied from the first suction gas line 101 . In addition, the second ejector 60 may combine the vaporized gas at the rear end of the vaporizer 83 and the gaseous boil-off gas supplied from the second suction gas line 102 to discharge gaseous fuel gas.

The accumulator 70 is a device for storing high-pressure gas, temporarily storing boil-off gas that has passed through the first ejector 50 and the second ejector 60 and supplying it to the second consumer 30 when necessary. It can be a storage device.

The heat exchanger 82 is a means for converting the fuel gas supplied to the second consumer 30 into a temperature condition required by the second consumer 30, and is disposed between the accumulator 70 and the second consumer 30. It can be. The heat exchanger 82 passes through the third ejector supply line 208 by performing heat exchange with seawater flowing through the third cooling line 303 branched from the rear end of the fresh water pump 81 of the first cooling line 301. The temperature of the fuel gas can be controlled.

Therefore, the liquefied gas regasification system according to the present invention uses the liquefied gas pressurized through the high-pressure pump 44 as a driving fluid to suck BOG generated in the storage tank 10 without power, and then to a second consumer such as a power generation engine ( 30), and through this, the power generation engine can be driven without equipment such as expensive compressors necessary for driving the power generation engine, thereby securing economic feasibility in system configuration.

In addition, by providing the ejectors 50 and 60 instead of the compressor to process the surplus BOG, construction costs can be reduced, power consumption can be reduced, and the failure rate is very low, resulting in improved driving reliability.

In addition, when fuel is required, including a configuration for the first ejector 50 and the second ejector 60 that utilize different fluid flows as driving fluid and the accumulator 70 that mixes and supplies them to the engine It is possible to supply fuel to the second consumer 30 only limitedly.

The present invention has been described with reference to an embodiment shown in the accompanying drawings, but this is only exemplary, and those skilled in the art can make various modifications and equivalent other embodiments therefrom. You will understand. Therefore, the true scope of the present invention should be defined only by the appended claims.

10: storage tank 20: first demand
30: second demand point 40: re-liquefaction unit
41: compressor 42: recondenser
43: supply pump 44: high pressure pump
50: first ejector 60: second ejector
70: accumulator 81: fresh water pump
82: heat exchanger 82a: first heat exchanger
82b: second heat exchanger 83: vaporizer
100: boil-off gas line 101: first suction gas line
102: second suction gas line 200: fuel gas supply line
201: first fuel gas supply line 201a: return line
201b: return valve 202: second fuel gas supply line
203: third fuel gas supply line 204: fourth fuel gas supply line
205: recovery line 206: first ejector supply line
207: second ejector supply line 208: third ejector supply line
300: cooling line 301: first cooling line
302: second cooling line 303: third cooling line

Claims (7)

A storage tank in which liquefied gas is stored;
a fuel gas supply line connecting the storage tank and a consumer;
After re-liquefying the BOG stored in the storage tank using a recondenser, the fuel gas
Boiled gas line sent to the supply line; and
An ejector supply line branched from the fuel gas supply line and connected to the consumer, provided with an ejector that sucks the BOG stored in the storage tank and sends fuel gas toward the consumer, and
the ejector
A first ejector provided in a first ejector supply line branching from the fuel gas supply line, mixing the passing liquefied gas with BOG and sending it toward the consumer;
A second ejector provided in a second ejector supply line for sending boil-off gas that has passed through the vaporizer in the fuel gas supply line toward the consumer, mixing BOG and sending it toward the consumer; and
The ejector supply line is
And an accumulator in which the gas passed through the first ejector and the second ejector is stored.
A liquefied gas regasification system in which a heat exchanger is provided between a rear end of the first ejector and the second ejector and a second consumer. delete According to claim 1,
The demand is
a first consumer connected to the fuel gas supply line; and
A liquefied gas regasification system comprising: a second consumer that requires fuel having a pressure condition or temperature condition different from that of the first consumer and is connected to the ejector supply line. delete delete According to claim 3,
The fuel gas supply line
A supply pump for pumping liquefied gas inside the storage tank, a high-pressure pump for pressurizing liquefied gas under pressure conditions required by the first consumer, and a vaporizer for vaporizing liquefied gas passing through the fuel gas supply line are installed Liquefied gas regasification system. According to claim 6,
A liquefied gas regasification system further comprising a cooling line for exchanging heat energy with a heat exchanger provided in the vaporizer or ejector supply line using seawater.

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