For the air circulation refrigeration nitrogen liquefaction process, the influence of flow, temperature and pressure of raw nitrogen on liquid nitrogen yield and nitrogen liquefaction rate were investigated by using ASPEN HYSYS software. The simulation results show that after the equipment starts at 110 min, the nitrogen temperature reaches the liquefaction temperature of about 175 ℃; the raw nitrogen flow greatly affects the raw nitrogen pressure, which can be almost ignored at room temperature.
