Rolling Heating Furnace Temperature Control System Research

Reheating furnace is one of the most important equipment in steel rolling plant. It is used for billet heating, and then for the rolling mill. The heating effect of the heating furnace largely determines the quality of the products of a rolling. Along with the progress of society, Industrial demand of the heating furnace’s heating effect is higher and higher, but the traditional PID control is not up to the control system in temperature control of large delay and strong coupling. This paper, combining with the actual industry, studied about combustion strategies, detecting element, controller selection. The paper designed a heating furnace control system based on the strategy of PLC adopts double cross limit combustion and fuzzy PID temperature controller.Firstly, this paper describes the history and current situation of the heating furnace. Three different combustion strategy was put forward according to the requirements of heating furnace technology and combustion mechanism:Cascade ratio control, single cross limit control, double cross limit control. After theoretical analysis and experimental research, draw the conclusion that double cross limiting heating furnace control system can make full combustion of fuels is not excess air.Then, the issue studied the PID controller, fuzzy control theory, a fuzzy PID controller. In the design of fuzzy PID controller, according to input and output, to determine the membership function and fuzzy rules. According to the double cross limit combustion control system model, temperature controller using PID control and fuzzy PID control to simulate respectively.Comparative conclusions, the fuzzy PID controller is better. Therefore, we decided to adopt fuzzy PID temperature controller in the design.Finally, Engineering application Siemens S7-300PLC. PC using MCGS software to complete the function of data calculation, alarm and security mechanism, display screen monitor, report printing, and so on. Lower machine programming is divided into two categories, automatic control and manual control, main designed the automatic control for temperature regulation first, then doing a furnace pressure control. Realizing the three functions of calculating E and EC, calculate the fuzzy E and EC, and output the PID, the fuzzy PID control is realized. The simulation and experimental results show that:the combustion control system that based on the fuzzy PID control, which designed by this paper can improve the effective quality control of heating furnace.