REDUCTION OF ENERGY COSTSBY OIL RECTIFICATION PLANT СONTROL
Introduction. Methods for assessing the energy efficiency of small oil refineries are not sufficiently developed currently. Aim is an optimizing the energy costs of oil separation. Materials and methods. An algorithm for calculating the sectional model of the atmospheric unit of a low-power oil distillation unit is presented. The resulting model is supplemented by the calculation of an air-cooling apparatus and a shell-and-tube heat exchanger. The factors affecting energy costs were selected: the consumption of superheated water vapor in the atmospheric and stripping columns, reflux ratio, and the consumption of raw materials. To derive the dependence of the selected criterion on the listed factors, the method of orthogonal central compositional planning of the experiment was applied. A planning matrix for a four-factor experiment using the sectional model is compiled. The results of the experiment have been obtained in the MATLAB software package. An estimation of the insignificance of the coefficients in the obtained second-order regression equation is carried out; insignificant coefficients are excluded from the model. The adequacy of the model was verified using the Fisher criterion. The regression equation represented in the physical quantities of the factors is the objective function. Results. The surface of the output parameter is constructed depending on control factors (reflux number and flow rate of superheated water vapor into the atmospheric column) with a constant flow of raw materials and a constant flow of superheated steam into the stripping column. It is shown that the selected factors affect not only energy costs, but also the quality indicators of petroleum products. Mathematical models are given for determining the quality indicators of oil products (temperatures of the beginning and end of boiling) at an oil refinery, which are used as limitations. The application of the obtained dependence is proposed for optimizing energy costs at an oil distillation unit with a changing consumption of raw materials. Conclusion. The obtained optimal values of the factors can be used as tasks for the regulators on the current installation.