In the whole process of the cryogenic air separation unit, the air compression system is the most power consuming link, and its power consumption accounts for 50% - 70% of the total energy consumption of the unit. The core is the superposition of working characteristics, energy loss and process requirements.
Firstly, the compression process consumes a lot of energy. The air for cryogenic air separation needs to be compressed to 0.5~0.6MPa to meet the subsequent liquefaction and rectification demands. Air compression is a high energy consumption physical process. The power consumption increases by 7% for each pressure rise of 0.1bar, and only about 10% of the electric energy is converted into effective compression energy, and the rest is wasted by heat energy.
Secondly, operating losses push up power consumption. The system has hidden losses such as air intake resistance, mechanical wear and pipeline leakage, which need additional power consumption to make up; The shaft power of the air compressor will increase by about 1% when the ambient temperature rises by 3 ℃, and the humidity and impurities will also increase the burden of energy consumption.
In addition, the system requires 24h continuous and stable operation, the air compressor frequently loads and unloads additional power consumption, and its energy consumption base is far higher than the follow-up link, so it becomes the core link of the most power consuming of the deep cooling air separation.