摘要:
Provided is a boil-off gas reliquefaction device that devises a disposition of equipment to be installable even in existing LNG carriers and that has a refrigeration cycle unit that reduces thermal load, is compact, and is highly efficient. The boil-off gas reliquefaction device (1) has: a liquefaction processing unit (5) having a BOG supply pipework (35), a fuel compressor (33), and a BOG transport pipework (39); and a refrigeration cycle unit (3) that further lowers the temperature of a coolant from a coolant compressor (6) by means of an expander (13) and that has a condenser (17) that cools BOG passing through the BOG transport pipework (39). The liquefaction processing unit (5) is provided with a BOG precooler (57) that performs heat exchange between BOG passing through the BOG transport pipework (39) on the upstream side of the condenser (17) and BOG passing through the BOG supply pipework (35). The refrigeration cycle unit (3) is provided with: a booster compressor (19) that is driven on the downstream side of the condenser (17) by the expander (13); and a second aftercooler (29) that cools the coolant from the booster compressor (19).
摘要:
A method for starting and operating a plant for the liquefaction of a gaseous product comprising the steps of electrically connecting a variable frequency drive to a motor of a first machine string; increasing the speed of the motor of the first machine string up until a first predefined threshold; electrically disconnecting the variable frequency drive from the motor of the first machine string; electrically connecting the variable frequency drive to a motor of a second machine string; the first predefined threshold is function of said frequency of the power supply grid. The variable frequency drive can be switched during operation of the plant among the strings according to process requirements.
摘要:
Described herein are systems and processes to produce liquefied natural gas (LNG) using liquefied nitrogen (LIN) as the refrigerant. Greenhouse gas contaminants are removed from the LIN using a greenhouse gas removal unit. The LNG is compressed prior to being cooled by the LIN.
摘要:
Disclosed is a ship including a storage tank for storing a liquefied gas. The ship includes: an boil-off gas heat exchanger installed on a downstream of the storage tank such that compressed boil-off gas (hereinafter, referred to as "first fluid") is made to exchange heat and cooled using boil-off gas, which is discharged from the storage tank, as a refrigerant; a compressor installed on a downstream of the boil-off gas heat exchanger so as to compress a part of the boil-off gas discharged from the storage tank; an extra compressor installed on a downstream of the boil-off gas heat exchanger in parallel with the compressor so as to compress the other part of the boil-off gas discharged from the storage tank; a refrigerant heat exchanger for additionally cooling the first fluid that is cooled by the boil-off gas heat exchanger; a refrigerant decompressing device which expands the second fluid, which is sent to the refrigerant heat exchanger (hereinafter, referred to as "second fluid") and cooled by the refrigerant heat exchanger, and then sends the second fluid back to the refrigerant heat exchanger; a first decompressing device which expands a part of the first fluid, which is cooled by the boil-off gas heat exchanger and by the refrigerant heat exchanger; and a third decompressing device which expands the remaining part of the first fluid, which is cooled by the boil-off gas heat exchanger and by the refrigerant heat exchanger, and sends the expanded remaining part of the first fluid back to the refrigerant heat exchanger, wherein the refrigerant heat exchanger heat-exchanges the first fluid to cool the first fluid, using the second fluid, a fluid expanded by the refrigerant decompressing device, and a fluid decompressed by the third decompressing device as a refrigerant; the first fluid is boil-off gas compressed by the compressor or is a confluent flow of the boil-off gas compressed by the compressor and the boil-off gas compressed by the extra compressor; and the second fluid is the boil-off gas compressed by the extra compressor or a confluent flow of the boil-off gas compressed by the compressor and the boil-off gas compressed by the extra compressor.
摘要:
Provided is a liquefaction method, a liquefying apparatus, and a floating liquefied-gas production facility equipped with the same, with which it is possible to suppress a decrease in liquefaction efficiency when gas to be liquefied is liquefied, to ensure safety, and to make the facility compact. Gas to be liquefied that has been subjected to heat exchange with a high-pressure heating medium composed of a single component is reduced in pressure, after which the gas to be liquefied that has been reduced in pressure is made to exchange heat with a low-temperature-side heating medium that is lower in temperature than and of the same type as the high-pressure heating medium.
摘要:
Disclosed herein is a boil-off gas treatment system. The boil-off gas treatment system includes a compressor compressing boil-off gas generated in an LNG storage tank of a ship or a floating structure, a heat exchanger cooling the compressed boil-off gas through heat exchange with boil-off gas to be supplied to the compressor, an expansion unit performing adiabatic expansion of the boil-off gas cooled by the heat exchanger, a gas-liquid separator performing gas/liquid separation of the boil-off gas subjected to adiabatic expansion by the expansion unit and supplying liquefied natural gas to the LNG storage tank, and a bypass line through which the boil-off gas subjected to adiabatic expansion is supplied from a downstream side of the expansion unit to a downstream side of the gas-liquid separator.
摘要:
A method for producing electrical energy in a combined energy generation plant (100, 200) which comprises an air treatment unit (10) and a power station unit (20) is proposed. In a first operating mode, air (AIR) is liquefied to form an air liquefaction product (LAIR) and, in a second operating mode, an air liquefaction product (LAIR) is converted into a gaseous or supercritical state, in which said product is introduced into the power station unit (20) and is used for producing electrical energy. In a third operating mode, air (AIR) is condensed in the air treatment unit (10) and used in the power station unit (20) directly for producing electrical energy. It is envisaged that, in the first operating mode, the air (AIR) is cooled to several temperature levels (T1 - T5) by two liquid coolants and the air liquefaction product (LAIR) is correspondingly heated. In addition, in the first operating mode, the air (AIR) is condensed stepwise over several pressure levels (LP, MP, MP1, HP). In addition, in the second operating mode, the air liquefaction product (LAIR) is heated to a further pressure level (HP1) and introduced into the power station unit (20) at this pressure level in gaseous form. Finally, in the third operating mode, the air (AIR) is introduced into the power station unit (20) in separate batches and at different pressure levels (MP1, HP or HP1). A corresponding energy generation plant (100, 200) is likewise the subject matter of the invention.
摘要:
A first nitrogen stripper feed stream is fed into a nitrogen stripper column at a stripping pressure. A nitrogen-stripped liquid is drawn from a sump space of the nitrogen stripper column, depressurized to a flash pressure that is lower than the stripping pressure, and fed to an end flash separator. A liquefied hydrocarbon product stream is discharged from the end flash separator, as well as a process vapour. The process vapour is compressed to at least the stripping pressure, and, split in a stripping vapour stream and a fuel gas vapour stream. The stripping vapour stream is fed into the nitrogen stripper column, while the fuel gas vapour stream is passed to a gas turbine. Another fuel gas, having a lower heating value, is obtained from the overhead vapour from the nitrogen stripper column. This other fuel gas is combusted in a combustion device other than a gas turbine.
摘要:
A boil-off gas (BOG) stream (15) from a liquefied hydrocarbon storage tank is split into a BOG heat exchanger feed stream (25) and a BOG bypass stream (35). The BOG heat exchanger feed stream (25) is heat exchanged in a BOG heat exchanger (40) against a process stream (135), thereby providing a warmed BOG stream (45) and a cooled process stream (195). The warmed BOG stream (45) is combined with the BOG bypass stream (35) to provide a temperature controlled BOG stream (55). Herein, the mass flow of the process stream (135) is controlled in response to a measured first temperature of at least one of (i) the warmed BOG stream (45) and (ii) the cooled process stream (195) to move the measured first temperature towards a first set point temperature; and the mass flow of one or both of the BOG heat exchanger feed stream (25) and the BOG bypass stream (35) are controlled in response to a measured second temperature of the temperature controlled BOG stream (55), to move the measured second temperature towards a second set point temperature.