SIMULATION OF AN AUTOMATIC TEMPERATURE CONTROL SYSTEM FOR THE STABILIZATION CATALYSATE PROCESS IN CONDITIONS OF UNCERTAINTY

The relevance of the work is caused by the necessity to take into account the influence of disturbances (changes in the quality of the unstable catalysate, the quality of the fuel gas) on temperature control in the lower part of the stabilization column of the catalysate stabilization unit of the catalytic reforming unit. The temperature of the bottom of the stabilization column is an important characteristic of the catalysate stabilization unit, which indicators characterize the quality of functioning of the entire reforming complex. The peculiarity of the control object under consideration consists in the qualitative information contained in the input values and disturbing influences, which include the state of the tubular furnace, the content of benzene-forming substances in the unstable catalysate, the quality of the unstable catalysate, and the quality of the fuel gas. This information is evaluated by operators based on the experience of technologists, taken into account in the form of linguistic parameters based on the results of a survey of experts and represented by membership functions. The influence of perturbations is proposed to be considered in terms of the parameters of the transfer function of the control system based on robust stability methods. It is assumed that these coefficients change over time under the influence of perturbations. At the same time, the task of studying the robust stability under temperature control is important. Objective: to provide a stable temperature control regime for stabilization column under conditions of uncertainty. Object: unit for catalysate stabilization of a catalytic reforming unit with continuous catalyst regeneration. Methods: theory of catalytic reforming, modeling, automatic control theory, systems analysis, computational mathematics. Results. The paper posed and solved the problem of studying the stability of the temperature control of the stabilization column under conditions of uncertainty. The characteristic of the scheme of catalysate stabilization is given. The control object is analyzed, the variables are distributed into groups as vectors, and the features of the control object are marked. The robust stability is investigated, the simulation results are presented, and the stability radius is determined, which makes it possible to ensure a stable operation of the automatic temperature control system of the lower part of the column under uncertainty.