摘要 |
Cryogenic liquefying/refrigerating method and system, wherein temperature of gas-to-be-liquefied at the inlet of the compressor for compressing the gas is reduced by cooling the gas discharged from the compressor using a high-efficiency chemical refrigerating machine and vapor compression refrigerating machine before the gas is introduced to a multiple stage heat exchanger thereby reducing power input to the compressor and improving liquefying/refrigerating efficiency. Gas-to-be-liquefied compressed by a compressor is cooled by aftercooler, and further cooled by an adsorption refrigerating machine which utilizes waste heat generated in the compressor and by an ammonia refrigerating machine 40 , then the high pressure gas is introduced to a multiple-stage heat exchanger where it is cooled by low pressure low temperature gas separated from a mixture of liquid and gas generated by adiabatically expanding the high pressure gas through an expansion valve 30 and returning to the compressor, and a portion of the high pressure gas is expanded adiabatically by expansion turbines in mid-course of flowing of the high pressure gas through the stages of the heat exchanger to be joined with the low pressure low temperature gas returning to the compressor.
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