| 摘要 |
<p>A process is disclosed for liquefying natural gas to produce a pressurized liquid product having a temperature above -112 °C using two mixed refrigerants in two closed cycles, a low-level refrigerant to cool and liquefy the natural gas and a high-level refrigerant to cool the low-level refrigerant. After being used to liquefy the natural gas, the low-level refrigerant is (a) warmed by heat exchange (65) in countercurrent relationship with another stream of the low-level refrigerant and by heat exchange (65) against a first stream of the high-level refrigerant, (b) compressed to an elevated pressure, and (c) aftercooled against an external cooling fluid. The low-level refrigerant is then cooled by heat exchange (65) against a second stream of the high-level mixed refrigerant and by exchange against the low-level refrigerant. The high-level refrigerant is warmed by the heat exchange with the low-level refrigerant, compressed (67) to an elevated pressure, and aftercooled against an external cooling fluid (69).</p> |
