Mathematical model of sheet metal strip heating by attacking jets

Abstract

The authors investigated the intensity of heating of a moving strip of thermally thin metal on a finite length section by a system of attacking neutral gas jets. The article is devoted to solving the problem of creating a system for heating a strip of moving metal by attacking jets of neutral gas by estimating the intensity of heating a metal strip using mathematical modeling methods. The main options for heat treatment of sheet metal are named. The article describes the differential heat conduction problem and its subsequent simplification, considering the assumptions made to obtain an effective calculation algorithm; the empirical relations selected for calculating local and average values of heat transfer coefficients; and the basic parameters for variant calculations. For comparative modeling, a 20m-long section was considered, where a strip entering with a temperature of 500 °С is heated by neutral gas with temperature of 800 °С. The results of calculating the dependence of average cross-sectional temperature of the strip on its movement speed (in the range from 0.1 m/s to 2 m/s) at two values of the gas flow velocity (20 m/s and 40 m/s) are presented, on the basis of which the authors concluded that acceptable heating intensity is achieved only at low speeds of the strip, and the gas flow rate (in the considered range) is not a reserve for a significant increase in this intensity.