Fluid catalytic cracking unit (FCCU) is one of the key processes in modern petroleum refinery

where reaction-regeneration system is the core technology. Researches about reaction-regeneration system are very active in domestic and abroad

but mainly focusing on the influences of process parameters on reactive process. Reaction-regeneration system is a complex system due to its multivariable

time-varying and nonlinear characteristics

and thus the modeling of the system of complex kinetics reactions should be studied. A dynamic model is put forward to study the operating characteristics of system. Based on the equations of material balance

energy balance

general mechanism mathematical models are established. With field data and MATLAB software to solve the kinetic parameters

a user-friendly simulation system is developed and a steady-state production is achieved. With the established simulation system as the platform

four frequently encountered abnormal conditions are simulated and their influences on some important parameters are obtained. These parameters are plotted into curves and fitted into formulas and the theory of just-in-time is applied to the dynamic nonlinear analysis. Results show that the study of dynamic security analysis of abnormal conditions in the reaction-regeneration system is effective. The simulation of process is realistic in observing changes caused by abnormal operating conditions. When the changes of important parameters are known

the theory of JIT can infer certain abnormal conditions within a certain range

and draw the changes of the specific parameters during this abnormal condition. The processes running in different states are identified effectively. The accuracy and validity of the mathematical model are tested. This paper provides a new method for the identification of dynamic systems.