High Efficiency And Energy Saving Optimization And Application Of Air Separation Unit

Industrial gases are vividly compared to the "blood" of industrial processes,and the air separation unit can be regarded as the "heart" of the gas production.However,the energy consumption of the air separation unit is usually very large.In the coal chemical industry,the energy consumption of the oxygen production accounts for 10%-15%of the total energy consumption;moreover,the power consumption of the air separation unit occupies 15%-20%of the total power consumption of the iron and steel enterprises.Therefore,on the basis of meeting the original technical indicators,adjust and improve the production process of the system,effectively adjust the balance between supply and demand of products,so as to achieve energy saving and consumption reduction in a real sense,and provide objective support and help for the sustainable development of the industry.Most of the air separation devices use air compressor,air cooling tower,molecular sieve adsorber,turbo-expander,regular packing tower(medium pressure tower,low pressure tower,crude argon tower,refined argon tower)to produce oxygen,nitrogen and argon to meet customer needs.In this thesis,some researches and applications of the efficiency optimization are performed on the optimizable parts of the air separation unit considering the operation characteristics of the air separation unit.Considering the actual operating capacity of the air separation unit,the characteristics of the peak-valley time-of-use(TOU)electricity price are fully used to achieve the varying-condition adjustment of the air separation unit load when the market demands of liquid oxygen and nitrogen change;therefore,the overall electricity cost of the production is decreased and the income is increased.Inspired by the sequential control of the molecular sieve adsorption system,deep analysis is performed about the start of the liquefaction system of the air separation unit.The column is divided in a section-division and item-division way,which helps to achieve one-button sequential control start.As a result,the intensity of manual operation is decreased significantly,and the misoperation risk can be also reduced to zero;moreover,this can make the air separation operate in an effective and energy-saving manner.