| Based on the equation of furnace energy balance and the heat exchange equation of billet and fender, the simplified model is established which simulates the thermal process of the furnace (i.e. ternary model), and the temperature of furnace gas, the temperature field of billet and fender (i.e. the section temperature distribution) are solved.Applying the concept of radiation exchanged area to the thermo junction surface of thermocouple, the furnace temperature formula is deduced to achieve the dynamic description of furnace temperature. For derivation, the assumption that the fender is a reradiating surface is relieved, which can make the significance of the formula more general.For the two aspects described above, the heating furnace software platform is constituted, making a condition to off-line closed loop research on DDC system based on furnace temperature control, and several methods of PID parameter setting on the software platform are researched. In addition to the change of furnace temperature setting value, various "impact" model by random number was applied to simulate the random dynamic working condition such as the output changes and the heat value fluctuation during the production process.On the basic of indirect problem method of heat transfer, a preliminary study to the identification of blanket heat absorptivity is conducted, which is a significant parameter of heating furnace SCC system. The thought of making the basic identification of blanket heat absorptivity by the steady state simulation of software platform and making the compensated identification of blanket heat absorptivity by dynamic simulation was set forth.The off-line study of control algorithm in the method of software platform can help to reduce the debug range and the debug time during the local debugging, and consequently to reduce the negative influence on production. Furthermore, the model method and relevant software can be used as a script of heating furnace(SCC+DDC) controlling system CAI. |
