A SYSTEM FOR COOLING NATURAL GAS WITH A MIXED REFRIGERANT

Claims

This description relates to a system for cooling natural gas and refers specifically, but is not limited to, a system for cooling natural gas to liquefaction through heat exchange in a multi-flow heat exchanger with a mixed refrigerant. The system comprises a closed thermodynamic refrigeration cycle, in which the mixed refrigerant is cooled through cyclic thermodynamic transformations, including compression, cooling, condensation, expansion, and vaporization stages, with the compression stage being a two-stage compression.The multi-stream heat exchanger is provided with: - a hot natural gas passage; - a cold mixed refrigerant passage; and - a plurality of hot passages for pre-cooling corresponding mixed refrigerant streams from different compression stages, each stream being connected to a respective expansion device and separator, the expansion device being configured to expand and at least partially to the instantaneous expansion of the mixed refrigerant and subsequently cool the mixed refrigerant, the separator being configured to separate the mixed refrigerant into a liquid fraction and a vapor fraction, which are finally directed to the cold mixed refrigerant passage.