| 摘要 |
PURPOSE: Liquefaction of a natural gas accompanying dewatering of a feed is provided to give a liquefaction cycle which minimizes inconsistency of temperature in a lower part of MCHE and to improve an overall efficiency of the liquefaction cycle. CONSTITUTION: A method to dry and liquefy a natural gas stream (14) includes the following steps; (a) a step which cools a natural gas feed stream (10) which contains water to generate the cooled natural gas stream; (b) a step which additionally cools the cooled natural gas feed stream after removing water from the cooled natural gas feed stream to generate a dried and cooled natural gas stream (16); (c) a step which heats the dried and cooled natural gas stream to generate a dried and reheated natural gas stream (17); (d) a step which cools at least one of coolant feed streams which is compressed by indirect countercurrent heat exchange with a low temperature refrigerant which is expanded after cooling and liquefying the dried and reheated natural gas stream to generate a liquefied natural gas product stream (18), at least one or more of compressed refrigerant streams, and an expansion and heated coolant stream; (e) a step which additionally cools by expanding a low temperature refrigerant stream, which is compresses to supply the low temperature refrigerant which is expanded, or streams. |
