Novel operation control strategy for conjugate high-low pressure air separation columns at different part loads

摘要: Abstract Air separation industry can be considered as the major source provider of oxygen and nitrogen. It is an energy-intensive process that consumes a large amount electrical energy. So, this study concerning on doing improvements in both design control order to decrease specific energy demands products. Therefore, complete steady state simulation model heat integrated double distillation column cryogenic air unit using Aspen Plus software presented. The results are compared with typical real values showing good agreement maximum deviation 2.6%. Then, optimization procedure main factors columns proposed. This causing yields nitrogen increase from 95% 99.65% 90% 99.9% respectively while demand (at 8 bar) decreased 0.25 kW/Sm3 0.18 kW/Sm3. After that, sufficient system installed by simple single input output (SISO) PI controllers. links between controlled manipulated variables. Also, it includes novel operation strategy give plant ability operated under different production modes (liquid oxygen, liquid nitrogen, or both) at wide range partial loads (typically 100% 25%). A careful tuning critical controllers provided select most proper gain (K) integral time (IT) which achieve purities desired product quantities each case products within range. Finally, performance 42 cases presented for 24 h. These include loads. show optimized model, proposed system, during qualities allowable ranges. availability working any part load percentage led provision consumed.