Natural Gas Liquefaction System with Turbine Expander and Liquefaction Method Thereof

Abstract

A natural gas liquefaction system with a turbine expander is provided that can improve the efficiency of the whole refrigeration cycle by using the turbine expander, instead of the throttling process that uses the conventional Joule-Thomson throttling valve that is used as a final throttling means in a conventional natural gas liquefaction system, and a liquefaction method thereof. The natural gas liquefaction cycle provided with the turbine expander of the present invention comprises a compressor 100, at least one vapor-liquid separator 300 or 310, a plurality of heat exchangers 200, 210, 220, 230 and 240, at least one Joule-Thomson throttling valves (below to be called JT valve) 400 and 410, a turbine expander 500, and connecting lines composed of plurality of pipes P1, P2, P3, P4, P5, P6 and P7 to connect these components.