COOLING POWER CAPACITY CONTROL DURING NATURAL GAS LIQUEFACTION Russian patent published in 2020 - IPC F25J1/00 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to a method of controlling production of stream (31) of a liquefied natural gas product, obtained by extraction of heat from natural gas by indirect heat exchange with expanded heavy mixed coolant and expanded light mixed refrigerant. Method comprises making a control loop, comprising maintaining flow rate (31) of liquefied natural gas product with a dependent setting value, and maintenance of flow rates of heavy mixed coolant (60a) and light mixed coolant (65) at set values of operator (80, 81). Method further includes performing an override control loop comprising determining an override setting value (95') for the liquefied natural gas flow rate, and calculating an override setting value (80') for the heavy mixed coolant flow rate and the overriding setting value (81').

EFFECT: technical result is optimization of available power for compressor drive in cycles of mixed coolant.

9 cl, 3 dwg