Design And Application Study Of Instrument Control System For Dual Regenerative Walking-beam Reheating Furnace

Reheating furnace is main process equipment in the Metallurgical firm, and its control strategy is an important focus of research in process control field. Dual regenerative reheating furnace is a very typical complex industrial control object, and it have strong coupled, time- varying, multivariate, nonlinear, time delay , large inertia and other characteristics. Because furnace temperature distribution is difficult to measure, and there are many factors external disturbances, so reheating furnace is difficult to make accurate modeling and control. The experts and scholars engaging in metallurgical automation form all over the world have been continued efforts to obtain breakthrough from the theory and practice in reheating furnace control technology.The paper studies the process automation systems of dual regenerative reheating furnace in Chengde Xinxin Vanadium and Titanium Co., Ltd., and is directed at the technology Requirements of dual regenerative reheating furnace. After in-depth analysis of heating technics mechanism and being, the paper puts forward the optimized strategy and intelligent control of the furnace temperature, and puts forward optimized control of heating evaporative cooling. It not only solve the problem of temperature control and the control of evaporative cooling ,and the problem has nonlinear, strong coupling, time delay, uncertainty, but also save heating furnace energy consumption, ensure the best burning combustion system ,extend the life of heating equipment. In the basis of analysis and research of previous work, it carried out designing control system, programming software and on-site commissioning work practice. Research results have been put into practical application. Paper is divided into the following sectionsFirst, it introduces the techniques overview and technical indicators of the dual regenerative reheating furnace, expounds the structure of automatic control systems in detail. Second, it expounds Instrumentation and controlling item of the reheating furnace in brief. It designs the hardware configuration of the instrument control system, and expounds the basic functions of the control system. Due to using PCS7 control system, it introduced graphics configuration software (CFC) which using in the instrument control system. On this basis, it expounds combustion control systems and evaporative cooling system of the dual regenerative reheating furnace in detail. In the combustion control system, control strategy of temperature uses temperature - gas/air flow cascade control and master-slave control. Control strategy of the regenerative combustion uses temperature feed-forward double cross limiting control, and this control strategy can make up some weaknesses of the double-cross limiting control. The design of the furnace pressure control use self-learning control scheme. In the evaporative cooling system, it focuses on the research how to control drum level. It introduces dynamic characteristics of the drum level, and analyzes the three-element level control using on the drum level. In this based, it optimize and design the three-element level control. It can be greatly facilitate the on-site commissioning. Finally, the paper analyzes and summarizes the field data and field debugging situation, and it Propose a number of shortcomings and problem can being improved in the future.The application of the actual production shows that the design of dual-regenerative reheating furnace instrument control system is reasonable, reliable and it meets the technological requirements.