Air separation nitrogen generation system and air separation method

Abstract

The invention discloses an air separation nitrogen generation system and an air separation method, the system comprises a rectification lower tower, external air can enter the rectification lower tower through an inlet, and a first condensation evaporator is arranged in the bottom space of the nitrogen tower; liquid air discharged from the first outlet can be guided into the nitrogen tower from the bottom of the nitrogen tower; after nitrogen discharged from the third outlet enters the first condensing evaporator and is discharged, a first part flows back to the lower rectifying tower from the top of the lower rectifying tower, and a second part is guided into the nitrogen tower from the top of the nitrogen tower and / or is discharged through a liquid nitrogen outlet; a second condensation evaporator is arranged in the bottom space of the oxygen tower; air discharged from the second outlet is treated by the second condensation evaporator and then is guided into the nitrogen tower from the middle part of the nitrogen tower; liquid air at the bottom of the nitrogen tower can be guided into the oxygen tower from the top of the oxygen tower, an oxygen outlet is formed in the middle of the oxygen tower, and a liquid oxygen outlet is formed in the bottom of the oxygen tower. The air separation nitrogen generation system can prepare nitrogen, liquid nitrogen, oxygen and liquid oxygen at the same time, and various use requirements can be met.

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