Temperature Model And Process Monitoring Simulation Of Continuous Reheating Furnace

Reheating furnace is an important equipment in the process of steel smelting.The main purpose of reheating furnace is to heat billet to the temperature that can comply with rolling mill.Reasonable hearth and billet temperature not only can improve the quality of steel and production capacity but also reduce energy consumption and prolong service life of heating furnace.Establishing accurate temperature prediction model of regenerative heating furnace,which can indirectly measure the temperature of slabs so that the optimal control of heating process can be finished.This paper does the research on regenerative reheating furnace system.Firstly,a steel temperature prediction model based on total heat exchange factor is established.The model uses a dimensionless factor to calculate the complex heat transfer of steel in heating furnace.And then,set different parameters of total heat exchange factor can be set according to the difference of the furnace combustion condition.The heat of heating billet is mainly from the hearth.Accurate hearth temperature is very important for prediction of steel slabs temperature.The heat in the furnace is mainly transmitted by radiation since there is high temperature in the hearth.Radiation heat transfer is much more complex than the other two kinds of heat transfer modes.Hence,the most accurate mathematical model--zone model is selected to establish the hearth temperature prediction model in this paper.High temperature heat exchange field is described by the zone model which based on the direct exchange area.In order to meet the demand of rapidity of the model,the model is simplified and the radiation between the different models is ignored.Meanwhile,ternary method is established.The whole heating furnace needs to be divided into many ternary model to establish the hearth temperature model.The air intake of every zone is the input of the hearth temperature model,by using parameters of actual heating furnace,the temperature of hearth?wall and slabs can be calculated.PLC is selected as controller and MATAB is used to finish the calculation,the communication between them via OPC protocol,which can establish the semi-physical simulation platform of heating furnace.Through the simulation experiment of the simulation platform,the process data were obtained,and the monitoring of the production and operation state of the heating furnace can be carried out.A fault can be pretended to occur by reducing the calorific value of fuel or change the total heat exchange factor.A process monitoring is achieved through using data driven PCA and KPCA methods respectively.The results of simulation show that KPCA has better performance than PCA on fault detective radio due to the seriously nonlinearity caused by the high order of the model.