OPTIMIZATION OF CRYOGENIC AIR SEPARATION PLANTS WITH SIMULTANEOUS DEVELOPMENT OF EFFECTIVE EXPANDER-COMPRESSOR UNITS

Abstract

The using of expander-compressor units (ECU) in cryogenic and in particular in air separation plants allows to increase their power efficiency. A creation their most general mathematical model and technique of optimization settlement is necessary for wider introduction of ECU in technological circuits of plants. A statement of problem of conditional optimization of regime and design data of ECU is stated in view of restrictions. The assumptions simplifying the decision of problem are proved. It is shown that maximization of efficiency of ECU can be shown the decision of problems, search of optimum characteristics compressor and expander steps answering to their maximum efficiency. For definition of the geometrical sizes of impellers is used their resulted diameter. It is shown that the stationary points answering to maximum of efficiency of steps as functions of the resulted diameter coincide. A procedure of optimization settlement and designing of ECU with simultaneous development of cryogenic plant is considered.