FIELD: gas liquefaction. SUBSTANCE: process and device are related to liquefaction of natural gas having positive pressure above 56.2 kgf/sq.cm (atm). Natural gas is injected into gas-expansion machine to reduce its pressure and to recover work from expansion of natural gas in process of pressure reduction so that flow going out of gas-expansion machine can be cooled in sequence to lower temperature by its passage through number of cooling stages thanks to indirect heat exchange with at least one cooling agent till gas is completely condensed in substance in last cooling stage. EFFECT: design of more economic and efficient equipment to produce liquefied natural gas. 10 cl, 1 dwg
