Design And Application On Walking Beam Reheating Furnace Control System

Heating furmace is one of the key equipment of steel rolling production in the industry.The automatic control level directly influence Energy consumption,yield,quality,burning rate,scrap rate of steel rolling.Through using advanced automatic technology,how to improve the automatic control effect and level of heating furnace,ensure the heating quality,achieve high efficiency and energy saving,and reduce pollution,is the primary purpose of this thesis.The reconstruction project of the NO.2 heating furnace in Ansteel 1780 hot strip mill is taken as background,in this thesis.According to the control system characteristics of the technological process and control requirements,the overall structure and the function of control system ars designed,and the system hardware and parameters are configurated.Both the temperature,flow and pressure control system of the walking-beam-fumace,and the related equipments of sequential control,such as the charging machine,extractor,Walking beam,furnace door,are studied.Based on the automatic control of the walking-beam-furnace,the furnace temperature control model is further optimizedOn the basis of cascade control and double cross limiting control,the automatic operation of the air fuel ratio is introduced.These optimizations eliminate the effect of the calorific value fluctuation in temperature control,greatly improve the utilization rate of the fuel,thereby reduce the generation of waste gas,achieve the purpose of energy saving and environmental protection,and meet the requirements of rolling production.At last,PLC control system and upper monitor system are designed and implemented.Ansteel 1780 hot strip mill was constructed and put into production in October 1999,and this transformation was carried out in Octob'er 2015.After more than 1 years of production and optimal operation,the automation control system is running stably,various control functions successfully put into operation to achieve better heating furnace automation production,to meet the requirements of rolling production line.