FIELD: technological processes.
SUBSTANCE: invention relates to liquefaction of natural gas in compressor station conditions of main gas line. Natural gas liquefaction system includes fuel and pulse gas preparation unit, gas transfer unit with oil supply and fuel supply systems, down-pressure compressor and liquefaction unit, comprising four heat-exchanging devices: four-flow pre-cooling, double-flow process flow, three-flow cryogenic and two-flow final cooling, as well as expander-generator, rectification columns and separators of process and production flows. Oil supply and fuel supply system includes at least two interconnected gas-oil heat exchangers, first of which is connected to oil cooling system of compressor of gas transfer unit, and second – to oil cooling system of gas compressor unit engine. Lubricating oil cooler is connected to second gas-oil heat exchanger outlet. Controlled valves are installed ahead of liquefaction unit with function of switching off liquefaction unit and direction of natural gas flow through fuel and pulse gas treatment plant and, further, through oil supply and fuel supply system to inlet of gas transfer unit.
EFFECT: high thermodynamic efficiency of the GNC production process.
1 cl, 1 dwg
