摘要:
A drive system for a refrigeration compressor such as is used in a natural gas liquefaction plant, allowing the desired compressor speed and maximum turbine efficiency to be maintained throughout varying ambient temperature conditions. A gas turbine is used with an electric starter motor with drive-through capability located on a common drive shaft between the turbine and the compressor. A variable frequency drive (VFD) is connected between the electrical power grid and the electric motor for smooth startups, but also to allow excess turbine mechanical power to be converted to electrical power by the motor operating as a generator, and delivered to the grid at the grid frequency. Pulse width modulation technology may be used to reduce harmonic distortion in the VFD's output. The starter motor also functions as a helper motor when the turbine output is insufficient to drive the compressor at the rotational speed needed to meet throughput requirements.
摘要:
A process and apparatus for the liquefaction of natural gas including at least one liquid expander for providing expansion of a high-pressure stream and powering a generator capable of producing electricity to be used to drive a compressor located elsewhere in the liquefaction apparatus. Particularly, a liquid expander is used to expand a high-pressure refrigerant stream and to power an electrical generator. The electricity provided by the generator can be used to power a compressor located in the same or a different refrigeration cycle as the liquid expander.
摘要:
A gas pressurization system comprising a gas inlet valve configured to receive an inlet gas stream. A clean-up system is coupled to the gas inlet valve. A recovery heat exchanger coupled to the clean-up system. The recovery heat exchanger is configured to remove thermal energy from the inlet gas stream and cool the inlet gas stream to one of a pre-cooled gas and liquid stream. An expander coupled to the recovery heat exchanger is configured to expand the pre-cooled liquid stream. A refrigeration unit coupled to the expander and configured to cool the expanded pre-cooled liquid stream to a liquid phase. A buffer storage unit is coupled to the refrigeration unit. A pump is coupled to the buffer storage unit at a pump suction and has a pump discharge coupled to the recovery heat exchanger. A high-pressure storage unit coupled to the pump discharge downstream of the recovery heat exchanger.
摘要:
A process of liquefying a gaseous, methane-rich feed to a liquefied product is provided that includes adjusting the composition and the amount of refrigerant and controlling the liquefaction process using an advanced process controller based on model predictive control to determine simultaneous control actions for a set of manipulated variables.
摘要:
Natural gas liquefaction system employing electric motors as compressor drivers. A combination of motors and steam turbines can be powered by a cogeneration plant and employed as drivers.
摘要:
A method for liquefying a natural gas primarily including methane, preferably at least 85% of methane, the other components essentially including nitrogen and C2-C4 alkanes, in which the natural gas to be liquefied is liquefied by circulating at a pressure P0 no lower than the atmospheric pressure (Patm), P0 preferably being higher than the atmospheric pressure, in at least one cryogenic heat-exchanger (EC1, EC2, EC3) by a counter-current closed-circuit circulation in indirect contact with at least one stream of coolant gas remaining in the compressed gaseous state at a pressure P1 that is entering the cryogenic heat-exchanger at a temperature T3′ that is lower than T3, T3 being the liquefaction temperature of the liquefied natural gas at the pressure P0 at the output of said cryogenic exchanger, characterized in that the coolant gas includes a mixture of nitrogen and at least one other component selected from among neon and hydrogen.
摘要:
A process for liquefying natural gas by; a) causing it to flow through three series connected heat exchangers, where gas is cooled to T3; T3 is less/equal to the liquefaction temperature of natural gas at atmospheric pressure; and b) causing the closed circuit circulation of a first stream of refrigerant gas at a pressure P1 lower than P3 entering the third exchanger and leaving the first exchanger, the first stream obtained using a first expander to expand a first portion of a second stream at P3 higher than P2, the second stream flowing relative to the natural gas stream entering the first exchanger and leaving the second exchanger; and a third stream at a pressure P2 higher than P1 and lower than P3 flowing relative to the first stream, entering the second exchanger and leaving the first exchanger; c) the second stream at the pressure P3 obtained by compression.
摘要:
This disclosure is directed to a novel arrangement for equipment used to compress fluids. A single prime mover is connected to a plurality of compressors. A supply conduit with parallel branch conduits directs fluid to be compressed to at least two compressors and parallel output conduits from each compressor are connected to a common output conduit, which directs compressed fluids to at least one additional compressor.
摘要:
The present techniques are directed to a flexible liquefied natural gas (LNG) plant that may be tied to an external electric grid for importing or exporting electric power. Exemplary embodiments provide a method for producing LNG that includes producing a base load capacity of refrigeration capacity for LNG production from a first compression system. Electricity may be produced from a second compressor string if electricity is needed by an external power grid, or a second amount of refrigeration capacity may be provided by the second compressor string is natural gas feed is available and the external grid does not need power.
摘要:
A compressor plant with at least one gas turbine having a gas turbine compressor and with a steam turbine is disclosed, wherein a steam generation plant which is assigned to the gas turbine is operated with exhaust gases of the gas turbine, such that the steam generated in the steam generation plant drives the stream turbine. There is assigned at least one additional compressor for compressing a process medium. The compressor is connected directly to the gas turbine and/or the steam turbine such that the assigned compressor is driven in each case directly by the gas turbine and/or the steam turbine.