Background. Rolling production is one of the most energy-consuming at iron and steel enterprise. This is due to the high energy costs of heating the rolling strip caused by poor regulation of the heating process. Experimental methods to search rational heating modes at iron and steel enterprises in industrial production conditions are quite expensive and time-consuming. Therefore, an urgent task is to find rational heating modes that ensure a given metal quality by mathematical modeling.
Materials and methods. In the framework of this study, the coefficients of convective heat transfer have been determined by the method of computer simulation of the interaction of combustion product flows with a rolling mill using the Ansys Fluent software. An integrated thermal model of the direct flame heating zone has been developed using the Microsoft Excel software package and regression data analysis methods. The accuracy indicators of the integrated thermal model have been estimated by comparing them with experimental data obtained under operating conditions of a continuous hot-dip galvanizing unit.
Results. 23 rational modes of heating of a steel strip in the direct flame heating zone of a continuous hot-dip galvanizing unit have been developed based on an integrated complex thermal model, which increase the effective efficiency of the furnace part by 0,75 %. It has been found that the annual technical effect of all modes of operation of the unit is 72,04 thousand m3 of natural gas, the annual economic effect is 504,3 thousand rubles.
Conclusions. The vital task of searching for rational heating modes of a steel strip in the direct flame heating zone of a continuous hot-dip galvanizing unit ensuring a given metal quality has been solved by mathematical modeling. Based on the developed 23 rational heating modes, pilot industrial tests have been carried out at an iron and steel enterprise in industrial production conditions. The actual results of the pilot tests coincide with the theoretical results of the integrated thermal model. In order to rationalize heating modes and reduce natural gas costs, it is recommended to switch from zone control to fire control with the adaptation of modes depending on the processed variety.