Development of an automatic reflux ratio regulation system for the rectification column

Introduction. This article provides an overview of the methods of managing the primary petroleum refining. To improve separation efficiency was proposed to stabilize the reflux ratio in the rectifying column. Purpose of work. To develop a system for automatic regulation of the reflux ratio of diesel fuel sections in an atmospheric column of the refinery oil. To study the operating modes of an atmospheric column with the participation of the obtained automatic control system. Materials and methods. The article presented the features of the oil rectification process at the atmospheric unit of a small capacity refinery. The features of heat dissipation with intermediate circulation flash compared to a large-capacity unit will be shown in this article. The parameters of the facility were selected and divided into groups. A dynamic model of the section of shell-and-tube heat exchangers for heating oil with diesel fuel at a low-power refinery unit in the form of differential equations of heat balance has been developed to achieve the goal set work. An electrode dehydrator material balance equation has been compiled to find desalted oil consumption and saltwater consumption. The dependence of the reflux ratio of diesel fuel sections of the atmospheric column on the inlet and outlet temperatures of the atmospheric column circulation flash, the acute fractionation consumption, circulation flash, and oil fraction selection was obtained. The resulting model of the facility consists of two parts: the linear part of the electric dehydrator and heat exchanger section, which determines the temperatures of the coolants, and the nonlinear output part, which determines the reflux ratio depending on technological parameters. The proposed model makes it possible to investigate the effect of disturbances on the controlled parameters. The MATLAB/Simulink software product has been chosen as a tool to implement the model. A system of automatic regulation of the reflux ratio in MATLAB/Simulink has been built with the participation of the developed model of the study object. Conclusion. The results of modeling a system for automatic regulation of the reflux ratio of diesel fuel sections in the atmospheric column of a low-power refinery unit has been obtained, taking into account the peculiarities of the process under disturbance conditions.