Cryogenic large-scale air separation equipment​ is referred to as "air separation equipment", which uses air as raw material, converts air into liquid state by means of compression cycle deep freezing, and then gradually separates it from liquid air through rectification to produce oxygen, nitrogen and Inert gases such as argon.

Strictly speaking, the heat exchange system is designed with multi stream mixed media in the same heat exchanger, so that the heat transfer of each medium is automatically balanced and the energy consumption is the lowest. However, for the internal compression process, all heat exchangers will be high-pressure heat exchangers, which will increase the accumulation of investment.