FIELD: heat exchange.
SUBSTANCE: disclosed is a low-temperature air separation method in an air separation plant (100), which has system (10) of distillation columns with high-pressure column (11) and low-pressure column (12). Air supplied to system (10) is compressed to initial pressure level. Part of compressed air is subjected to first pressure increase at first temperature level higher than 0 °C, and then to two additional pressure increases at temperature level below first temperature level, and then expanded in column (11). Enriched with oxygen liquid is extracted from column (22). For the first pressure boost, first booster (2) is used, which is actuated using the first expansion machine (9), in which the additional portion of compressed to the initial air pressure level expands to the pressure level of the low pressure column. For two additional boosts of pressure first booster (5) and second booster (6) are used. Air enters second booster (6) at temperature level whereat it exits first booster (5).
EFFECT: technical result is reduction of losses during heat exchange.
13 cl, 3 dwg
