Soak-time estimation method using control output in heating furnace

Abstract

This paper proposes the soak time estimation method using the slope of control output in heat treatment process. The soak time is the time at which the center temperature of the steel and ambient temperature of the steel reach the target temperature. The center temperature of the steel is needed to find the soak time, but it is difficult to always measure because of the industrial furnace structure. By calculating the relation between soak time and control output, the proposed method can find the soak time using the control output, not the center temperature. To eliminate the noise generated by the Proportional-Integral-Differential controller (PID) controller and to calculate the smooth slope, the moving average filter was used. The proposed method was verified by comparing the estimated soak time and real soak time using the test data. Copyright ? The Korean Institute of Electrical Engineers.