Abstract:
The current task is to develop an optimal control system for the catalytic reforming process, which ensures the achievement of optimal ratios of the octane number of gasoline and production costs. The formulation of the problem of optimal control of the catalytic reforming process is performed, which is distinguished by using the generalized optimality criterion as the target functional. A hybrid mathematical model of the catalytic reforming process has been developed, which takes into account the influence of parameters characterizing production costs and the octane number of gasoline on the efficiency of the process and makes it possible to calculate the values of the generalized optimality criterion depending on the values of the input variables of the process. Based on LP-35-11/1000 model for installation, there have been obtained the maximum annual costs of 4.05 billion RUB and the minimum octane number of gasoline 92.83. A multicriterial choice of the temperature control system at the exit from the furnace is fulfilled. The algorithm for determining the settings of the temperature regulator at the exit from the furnace in various modes of the catalytic reforming process is synthesized. The method of optimal control of the catalytic reforming process is developed, which is characterized by the consideration of expert information in the formalization of fuzzy goals and constraints in process control and allows to calculate optimal control actions, according to the Bellman–Zade scheme depending on the values of the input variables of the process. Based on this technique, a vector of controls corresponding to the minimum of the generalized optimality criterion I = 0.964 is determined. The search of Pareto-optimal solutions for controlling the catalytic reforming process was carried out. Positive effects were obtained using the developed system of optimal control of the catalytic reforming process: decrease in average costs by 0.33 million RUB; increase in the average octane number by 0.53; decrease in the average value of the generalized optimality criterion by 0.025.
Keywords:catalytic reforming, generalized criterion of optimality, Pareto optimal solution, hybrid model, classical PID controller, fuzzy PID controller, optimal control system.