FIELD: liquefaction and storage of natural gas. SUBSTANCE: natural gas at high pressure enters vortex tube where it is divided into two flows: cold flow and hot flow. Cold flow in form of liquefied gas is drained from main to heat-insulated reservoir. Hot flow of gas is preliminarily cooled in throttle valve and in intermediate heat exchanger. Then it is condensed in coil due to heat exchange with liquid nitrogen of nitrogen shield and is drained to reservoir. Liquid nitrogen of nitrogen shield performs two functions: liquefaction of natural gas and prevention of external heat input from penetration into reservoir. Provision is made for closed nitrogen loop for delivery of liquid nitrogen to nitrogen shield in due time and liquefaction of natural gas from main; this loop consists of liquid nitrogen return line and gaseous nitrogen line. For recondensation of nitrogen vapor, use is made from Stirling refrigerating machine. Availability of closed nitrogen loop excludes contamination of environment because of avoidance of emissions of vapor of nitrogen shield beyond technological complex. EFFECT: enhanced efficiency; reduced operational cost; ecological safety; increased gas liquefaction coefficient. 2 cl, 1 dwg
