| 摘要 |
<p>The process comprises partly pre-cooling natural gas by heat exchange with a pre-cooling refrigerant contained in a pre-cooling cycle (123), liquefying natural gas by heat exchange with a liquefying refrigerant contained in a liquefying cycle (100), and sub-cooling the natural gas by heat exchange with a sub-cooling refrigerant contained in a sub-cooling cycle. The liquefying refrigerant comprises nitrogen and an additional compound of which a boiling point at atmospheric pressure is -20[deg] C to -60[deg] C and a crystallization temperature is = -80[deg] C. The process comprises partly pre-cooling natural gas by heat exchange with a pre-cooling refrigerant contained in a pre-cooling cycle (123), liquefying natural gas by heat exchange with a liquefying refrigerant contained in a liquefying cycle (100), and sub-cooling the natural gas by heat exchange with a sub-cooling refrigerant contained in a sub-cooling cycle. The liquefying refrigerant comprises nitrogen and an additional compound of which a boiling point at atmospheric pressure is -20[deg] C to -60[deg] C and a crystallization temperature is = -80[deg] C. A molar proportion of nitrogen in the liquefying refrigerant is = 98.5%. The liquefying refrigerant is expanded in expanding turbines, and is partially condensed in the expanding turbines. The pre-cooling cycle, liquefying cycle and/or sub-cooling cycle comprises a compressor driven by gas turbine generating fumes. A part of heat from fume is transferred to an absorption refrigeration machine, and the gas turbine produces fume at a temperature of = 510[deg] C and is aero-derivative gas turbine. The pre-cooling refrigerant is partly cooled by the absorption refrigeration machine. The turbine gas is fed into air and the air is cooled before feeding. Independent claims are included for: (1) an installation for producing liquefied natural gas; and (2) an use of a composition comprising carbon dioxide and hydrofluorocarbon for cooling and liquefying natural gas.</p> |
