According to an embodiment of the present invention, a system for treating liquefied gas includes: an evaporation gas supply line connected from a liquefied gas storage tank to a liquefied gas consumer; an evaporation gas compressor provided on the evaporation gas supply line, and configured to compress evaporation gas generated from the liquefied gas storage tank; an evaporation gas heat exchanger provided in the upstream of the evaporation gas compressor on the evaporation gas supply line, and configured to perform heat exchange between evaporation gas compressed by the evaporation gas compressor and collected along an evaporation gas collect line branching off from the upstream of the liquefied gas consumer, and evaporation gas supplied from the liquefied gas storage tank; a Joule-Thomson valve provided in the downstream of the evaporation gas heat exchanger based on a flow of evaporation gas collected along the evaporation gas collect line, and configured to primarily decompress evaporation gas compressed by the evaporation gas compressor; an evaporation gas expander configured to secondarily decompress evaporation gas primarily decompressed by the Joule-Thomson valve; and a gas-liquid separator configured to separate flash gas from evaporation gas decompressed by the Joule-Thomson valve. According to the present invention, the system for treating liquefied gas performs a first decompression of evaporation gas using the Joule-Thomson valve, and a second decompression thereof using the evaporation gas expander when liquefying the evaporation gas to sequentially perform an isenthalpic process and an isentropic process, thereby improving the efficiency of evaporation gas liquefaction, compared to perform the entire decompression process using the Joule-Thomson valve. In addition, rotational power generated by the evaporation gas expander driven by the introduction of evaporation gas may be used as power to the evaporation gas expander to reduce power, thereby the efficiency of the LNG treatment system.

A treatment system of liquefied gas

A fuel pump temperature is regulated by selectively directing liquid fuel to an expansion section to evaporate the liquid fuel and create a drop in temperature to thermally cool the fuel pump.

Approach for controlling fuel flow with alternative fuels

A LNG storage and regasification plant includes a reliquefaction unit in which boil- off vapors from the storage tanks are re liquefied and recycled back to the LNG storage tanks for tank pressure and Wobbe index control. Preferably, LNG cold is used for reliquefaction and operational flexibility is achieved by feeding a portion of the pressurized boil-off gas to a fuel gas header and/or to be recondensed by the sendout LNG.

Methods and configuration of boil-off gas handling in lng regasification terminals

The present invention relates to a liquefied gas treatment system The liquefied gas treatment system comprises: an evaporative gas compressor which compresses evaporative gas supplied from a liquefied gas storage tank and supplies the evaporative gas to a first place where the evaporative gas is required; an evaporative gas heat exchanger performing heat exchange between the evaporative gas compressed in the evaporative gas evaporator and evaporative gas supplied from the liquefied gas storage tank; a pressure control part performing a first expansion process or a decompression process of the compressed evaporative gas; and a liquefaction part performing a second expansion process or a decompression process of at least one part of the evaporative gas supplied from the pressure control part The pressure control part expands or decompresses the evaporative gas up to the pressure required in a second place where a relatively low pressure is applied in comparison with the first place, and transfers the evaporative gas to the second place According to the present invention, the liquefied gas treatment system can enhance the efficiency of reliquefaction via an evaporative gas-evaporative gas heat exchange process and a two-stage expansion process without a separate reliquefaction means Furthermore, according to the present invention, the liquefied gas treatment system has an expansion apparatus for reliquefaction formed in two stages, can adjust pressure range in each stage, and thus can apply different ranges of working pressures to multiple places Accordingly, the use of evaporative gas can be maximized Furthermore, according to the present invention, the liquefied gas treatment system uses evaporative gas expanded in a first stage in a DFDE engine and reliquefies residual evaporative gas Accordingly, the liquefied gas treatment system can prevent evaporative gas from being easily consumed via a GCU or the like, and can prevent an increase in a load applied to the evaporative gas compressor, which can occur during a rejoining process of un-reliquefied evaporative gas

Disclosed is a fuel gas supplying system. The fuel gas supplying system can effectively dispose of or can effectively use evaporation gas. According to the embodiment of the present invention, the fuel gas supplying system includes: a storage tank accommodating liquefied gas and the evaporation gas of the liquefied gas; an evaporation gas supplying line including a compression unit compressing the evaporation gas and supplying the evaporation gas compressed by the compression unit to a first engine; a liquefied gas cooling line including a liquefied gas cooling unit cooling the liquefied gas; a reliquefaction line diverged from the evaporation gas supplying line and including an evaporation gas cooling unit receiving and cooling a part of the compressed evaporation gas, an expansion valve decompressing the evaporation gas cooled by the evaporation gas cooling unit, and a liquid-gas separator separating the evaporation gas, which is decompressed while passing through the expansion valve, to a gas component and a liquid component; a compressor compressing a refrigerant; a cooling unit heat-exchanging the refrigerant compressed by the compressor with at least one among the evaporation gas at a front end of the compression unit of the evaporation gas supplying line and the gas component separated by the liquid-gas separator; an expander decompressing the refrigerant heat-exchanged by the cooling unit; a cooling line enabling the refrigerant decompressed by the expander to pass through the evaporation gas cooling unit and the liquefied gas cooling unit and heat-exchanging the decompressed evaporation gas with the liquefied gas; and a temperature control line installed in the cooling line and including an opening and closing valve controlling a supply amount of the refrigerant supplied to the evaporation gas cooling unit and the liquefied gas cooling unit.

Fuel gas supplying system in ships

The present invention relates to a system for treating boil-off gas for a ship in which the boil-off gas that is discharged from a storage tank is pressurized and then most of the pressurized boil-off gas is used as the fuel of a high-pressure natural gas injection engine of the ship and the rest is returned to the storage tank through liquefaction with the cold heat of boil-off gas which is newly discharged from the storage tank so that the boil-off gas can be used efficiently. According to the system of the present invention for treating boil-off gas for a ship, which is provided with the storage tank storing liquefied natural gas and the engine using the liquefied natural gas stored in the storage tanks as the fuel, includes a first stream of the boil-off gas that is discharged from the storage tank after generation from the liquefied natural gas in the storage tank; a second stream of the boil-off gas that branches from the first stream and is supplied to the engine as the fuel when the amount of the first stream is greater than the amount of the fuel required by the engine; and a third stream of the boil-off gas that is a part of the first stream which is not supplied to the engine. The third stream is liquefied in a heat exchanger through heat exchange with the first stream, and thus the boil-off gas can be treated without having to use a re-liquefaction device having an additional refrigeration cycle.

System for treating boil-off gas for a ship

Disclosed is a liquefied natural gas storage apparatus. The apparatus includes a heat insulated tank and liquefied natural gas contained in the tank. The tank has heat insulation sufficient to maintain liquefied natural gas therein such that most of the liquefied natural gas stays in liquid. The contained liquefied natural gas has a vapor pressure from about 0.3 bar to about 2 bar. The apparatus further includes a safety valve configured to release a part of liquefied natural gas contained in the tank when a vapor pressure of liquefied natural gas within the tank becomes higher than a cut-off pressure. The cut-off pressure is from about 0.3 bar to about 2 bar.

LNG tank and operation of the same

Provided is a liquefied gas treatment system for a vessel, which includes a cargo tank storing liquefied natural gas (LNG), and an engine using the LNG as fuel. The liquefied gas treatment system includes: a compressor line configured to compress boil-off gas (BOG) generated in the cargo tank by a compressor and supply the compressed BOG to the engine as fuel; a high pressure pump line configured to compress the LNG stored in the cargo tank by a pump and supply the compressed LNG to the engine as fuel; and a heat exchanger configured to liquefy a part of BOG, which is compressed by the compressor, by exchanging heat with BOG that is discharged from the cargo tank and transferred to the compressor.

Liquefied gas treatment system for vessel

A fuel gas supply system of a ship is provided for supplying fuel gas to a high-pressure gas injection engine of a ship, wherein LNG is extracted from an LNG tank (1) of the ship, compressed at a high pressure via a first pump (2) and a second pump (4), gasified, and then supplied to the high-pressure gas injection engine The second pump is a high pressure pump which pressurizes the extracted LNG to meet the fuel gas pressure requirements of for the high-pressure gas injection engine, and a pressure control valve is installed in parallel with the second pump (4) in the fuel supply line (L1)

Fuel gas supply system and method of ship

Disclosed is a system for treating liquefied gas of a ship equipped with a storage tank for storing liquefied natural gas (LNG), and a main engine and a sub engine using the LNG stored in the storage tank as a fuel. The system for treating liquefied gas comprises: a first stream of boil-off gas which is generated from the LNG in the storage tank and discharged from the storage tank; a second stream of the boil-off gas from the first stream, which is supplied to the engine as the fuel; and a third stream of the boil-off gas from the first stream, which is not supplied to the engine. The first stream is compressed by a compressor and then divided into the second stream and the third stream. The third stream compressed by the compressor exchanges heat with the first stream in a heat exchanger and then is liquefied without use of a re-liquefying device that uses a separate coolant. All the liquefied third stream returns to the storage tank after being decompressed.

Choi Dong Kyu

Papers

System for treating boil-off gas for a ship

LNG tank and operation of the same

Liquefied gas treatment system for vessel

Fuel gas supply system and method of ship

System for treating a liquefied gas of a ship