Abstract: The total heat exchange factor(CF)is the important parameter for the L2 control system of reheating furnace. CF is influenced by the furnace structure parameters and operating parameters. So the compensation identification for CF is very important. The solo ternary model based on the furnace temperature was developed. Taking any model section of a ternary model， the temperatures of the furnace and of the slab surface were used as input conditions， the thermocouple model was developed and the energy equations of the thermocouple and furnace wall were established. Finally， the heat flux of slab surface was solved. So the identification for CF was researched. The influences for CF by the temperature， size of slab and the temperature change of the slab were researched. The results demonstrated that the value of CF decreased with the increase of the slab temperature， when the furnace temperature was constant. When the slab temperature was closed to the furnace temperature， the absolute value of the gradient for the variation of CF increased rapidly. While the slab temperature was constant， the value of CF increased with the increase of furnace temperature. Moreover， the CF increased with the increase of the length and width of the slab， and also increased with the increase of the emissivity for the slab.

Key words: solo ternary model, compensation identification, total heat exchange factor, furnace temperature, surface emissivity