integrally - geared compressors for precooling in lng applications

摘要

A natural gas liquefaction system is disclosed, which comprises at least a pre-cooling loop, through which a first refrigerant is adapted to circulate. The pre-cooling loop comprises at least one compressor for pressurizing the first refrigerant; at least one prime mover for driving the compressor; at least one condenser for removing heat from the first refrigerant; at least a first expansion element for expanding the first refrigerant; at least a first heat exchanger for transferring heat from natural gas to the first refrigerant. The system further comprises at least a cooling loop, downstream of the pre-cooling loop, where through a second refrigerant circulates. The natural gas is adapted to be sequentially cooled in the pre-cooling loop and in the cooling loop. The compressor of the pre-cooling loop is an integrally-geared turbo-compressor comprising a plurality of compressor stages.