Due to convenient storage and transportation of cryogenic liquid and simple operation, large equipment usually releases excess oxygen and nitrogen into liquid oxygen and nitrogen for nearby users or peak regulating use, which can greatly improve the utilization rate and economic benefits of oxygen and nitrogen. It's very impressive. Although the medium pressure process has a large investment, its advantages of low energy consumption and small footprint are more and more obvious with the increase of liquid production. Advanced and reasonable process organization, not only can long-term stable operation, but also large liquefaction, low energy consumption. Turbocharged turbo expander, small volume, less units, stable, safe and reliable, high efficiency, high liquefaction rate, low energy consumption per unit. Using cycle compressor, small volume, less units, stable, safe and reliable, high efficiency, low energy consumption per unit.