초록 ▼

A refrigeration system includes a plurality of heat exchangers (E1, E2, E3) in cascade, each of said heat exchangers including: a flow (150) of cold-producing liquefied methane; a high-pressure flow (122) of a two-phase mixture of refrigerant fluids giving up in heat and including refrigerant fluids

A refrigeration system includes a plurality of heat exchangers (E1, E2, E3) in cascade, each of said heat exchangers including: a flow (150) of cold-producing liquefied methane; a high-pressure flow (122) of a two-phase mixture of refrigerant fluids giving up in heat and including refrigerant fluids having a low normal boiling temperature; and a low-pressure flow (100) of a cold-producing two-phase mixture of said refrigerant fluids.

대표청구항 ▼

1. A refrigeration system comprising a plurality of heat exchangers in cascade, each of said heat exchangers comprising; a flow of cold-producing liquefied methane;a high-pressure flow of a two-phase mixture of refrigerant fluids giving up its heat and including refrigerant fluids having a low norma

1. A refrigeration system comprising a plurality of heat exchangers in cascade, each of said heat exchangers comprising; a flow of cold-producing liquefied methane;a high-pressure flow of a two-phase mixture of refrigerant fluids giving up its heat and including refrigerant fluids having a low normal boiling temperature;a low-presssure flow of a cold-producing two-phase mixture of said refrigerant fluids;means for expanding said cooled high-pressure flow at the outlet from said cascade and for directing at least a portion thereof to at least one refrigeration heat exchanger passing a gas including CO2, said heat exchanger operating in a frosting cycle;means for obtaining a liquid phase from said high-pressure flow for cooling; andmeans for expanding said liquid phase and directing at least a portion thereof into said at least one refrigeration heat exchanger, said heat exchanger operating in a defrosting cycle. 2. The refrigeration system according to claim 1, comprising one separator for obtaining a pressurized liquid phase of said mixture of refrigerant fluids, an expander suitable for causing the pressure of said liquid phase to drop, and means for redirecting at least a portion of said expanded liquid phase into said low pressure flow of a mixture of cold-producing refrigerant fluids. 3. The refrigeration system according to claim 1, comprising: a variable frequency compressor suitable for compressing said low-pressure flow at the outlet from said cascade: anda partial condenser suitable for condensing the mixture of refrigerant fluids compressed by said compressor in order to regenerate said high-pressure flow for introduction into said cascade. 4. The refrigeration system according to claim 1, wherein at least a portion of the mixture Of refrigerant fluids obtained at the outlet from said refrigeration heat exchanger operating in a defrosting cycle is used to top up said low-pressure flow of a mixture of refrigerant fluids at the inlet to at least one heat exchanger of said cascade, 5. A refrigeration system comprising a plurality of heat exchangers in cascade, each of said heat exchangers comprising: a flow of cold-producing liquefied methane;a high-pressure flow of a two-phase mixture of refrigerant fluids giving up its heat and including refrigerant fluids having a low normal boiling temperature;a low-pressure flow of a cold-producing two-phase mixture of said refrigerant fluids; andmeans for expanding said cooled high-pressure flow at the outlet from said cascade and for directing at least a portion thereof to at least one refrigeration heat exchanger passing a gas including CO2, said heat exchanger operating in a frosting cycle,wherein said low-pressure flow introduced into said cascade is obtained from the flow of a mixture of refrigerant fluids at the outlet from said refrigeration heat exchanger when it is operating in a frosting cycle. 6. The refrigeration system according to claim 5, comprising one separator for obtaining a pressurized liquid phase of said mixture of refrigerant fluids, an expander suitable for causing the pressure of said liquid phase to drop, and means for redirecting at least a portion of said expanded liquid phase into said low-pressure flow a mixture of cold-producing refrigerant fluids. 7. The refrigeration system according to claim 5, comprising: a variable frequency compressor suitable for compressing said low-pressure flow at the outlet from said cascade; anda partial condenser suitable for condensing the mixture of refrigerant fluids compressed by said compressor in order to regenerate said high-pressure flow for introduction into said cascade. 8. The system according to claim 5, comprising means for recovering a portion of the liquid phase of the low-pressure flow a mixture of refrigerant fluids at the outlet from said refrigeration heat exchanger. 9. The system according to claim 8, comprising: means for compressing said high pressure liquid phase;at least one evaporator suitable for vaporizing said high pressure liquid phase as obtained in this way; anda turbine suitable for expanding said high pressure vapor obtained in this way in order to produce mechanical energy. 10. A method of recovering cold from a flow of liquefied methane, wherein said flow is caused to flow through a plurality of heat exchangers also having flowing therethrough a high-pressure flow of a two-phase mixture of refrigerant fluids giving up its heat and including refrigerant fluids having low normal boiling temperatures, and by a cold producing low-pressure flow of a mixture of said two-phase refrigerant fluids, comprising the steps of: expanding said cooled high-pressure flow obtained at the outlet from said cascade; andusing at least a portion thereof in order to capture CO2 by frosting. 11. The method according to claim 10, comprising the steps of: separating said mixture of refrigerant fluids to obtain a pressurized liquid phase of the refrigerant fluid mixture;expanding the liquid phase as obtained in this way; andtaking therefrom at least a portion after expansion and redirecting it into said cold producing low-pressure flow of a mixture of refrigerant fluids. 12. The method according to claim 10, comprising the steps of: obtaining a liquid phase from said high-pressure flow that gives up its heat; andexpanding at least a portion thereof for use in defrosting the CO2. 13. The method according to claim 12, comprising taking at least a fraction of the mixture of refrigerant fluids used for said defrosting in order top up said low-pressure flow introduced into at least one heat exchanger. 14. The method according to claim 10, wherein the low-pressure flow introduced into the cascade is obtained from the flow of a mixture of refrigerant fluids that have been used for said frosting. 15. The method according to claimed 14, comprising taking a portion of the liquid phase of said high-pressure flow introduced into the cascade. 16. The method according to claim 15, comprising the steps of; compressing said liquid phase under high pressure;vaporizing the high pressure liquid phase as obtained in this way; andexpanding it in a turbine in order to produce mechanical energy. 17. The method according to claim 10, comprising the steps of: compressing at variable frequency the low-pressure flow obtained at the outlet from said cascade; andpartially condensing the mixture of refrigerant fluids as compressed in this way in order to regenerate said high-pressure flow introduced into said cascade. 18. The method according to claimed 12, comprising the steps of: separating said mixture of refrigerant fluids to obtain a pressurized liquid phase of the refrigerant fluid mixture;expanding the liquid phase as obtained in this way; andtaking therefrom at least a portion after expansion and redirecting it into said cold producing low-pressure flow of a mixture of refrigerant fluids. 19. The method according to claim 12, comprising the steps of; compressing at variable frequency the low-pressure flow obtained at the outlet from said cascade; andpartially condensing the mixture of refrigerant fluids as compressed in this way in order to regenerate said high-pressure flow introduced into said cascade. 20. The method according to claim 14, comprising the steps of; separating said mixture of refrigerant fluids to obtain a pressurized liquid phase of the refrigerant fluid mixture;expanding the liquid phase as obtained in this way; andtaking therefrom at least a portion after expansion and redirecting it into said cold producing low-pressure flow of mixture of refrigerant fluids.