New method for combustion control of walking beam reheat furnace

The improved cross limited combustion control method with rapid compensatory response function and anti-windup function was used in order to overcome the shortcomings of low load following speed of normal cross limited control method. An auto-tuning PID control algorithm was taken in respect of the furnace temperature process that has time varying and nonlinear properties, while an intelligent decoupling control method was applied to decouple the interaction between the low heat zone and the high heat zone. The application results show that the method increases control accuracy of each zone of reheat furnace and obtains the billet temperature that start-rolling requires as well as ensures economical combustion and safety operation.