The simulation and optimization of three - phase nonequilibrium model are discussed . the main research work and contributions of this dissertation are as follows : 1 . three novel equation - solving methods have been developed to solve the phase stability problem of ternary systems with satisfying robustness and rapidness 由于三相精馏过程涉及到液相稳定性问题,即初始液相是否会自发地分裂为二个液相,因此对于三相精馏过程的仿真及优化,首要的问题是判断液相数目。