| 摘要 |
Method and apparatus for liquefying a hydrocarbon stream. A liquefaction system comprises at least an NGL recovery system 12, a main refrigerant circuit 42 and a first refrigerant circuit 100, a pressure reduction device 52 followed by an end gas/liquid separator 62. The main refrigerant circuit 42 comprises at least one or more main refrigerant compressors 45, 45a, 45b, and the first refrigerant circuit comprises one or more first refrigerant compressors 101. A hydrocarbon feed stream 10 is passed through the NGL recovery system 12 to produce a methane-enriched overhead stream 20, which is subsequently cooled and liquefied by the first and second refrigerant circuits. The pressure of the liquefied stream is reduced and the resulting mixed-phase stream 60 is passed through the end gas/liquid separator 62 to provide an end gaseous stream 70 and a liquefied hydrocarbon product stream 80. The loading power of the one or more main refrigerant compressors and the one or more first refrigerant compressors is maximized to their maximum load by adjusting temperature of the liquefied stream to change the amount of end gaseous stream and by controlling an amount of the end gaseous stream being fed into the methane-enriched overhead stream 20 in a recycle stream 90b. |
