Design And Development Of The Software System For Optimization Control Of Shaft Furnace Roasting Process

The primary task of shaft furnace roasting process is to provide the roasted hematite with higher magnetism by high temperature deoxidization, and its effect is relative to the mental recovery and the concentrated ore grade. The shaft furnace roasting process has synthetic and complex characteristics, such as strong coupling, strong nonlinear, the operation condition varying frequently and so on. Perhaps the accumulation of the varieties of work-condition and improper operations will result in abnormal work-conditions, which will lead to the deterioration of the operation quality or even a total collapse of the control system if they cannot be detected and diagnosed on time. So the optimization control for shaft furnace roasting process is difficult. It is very important to study the optimization control for shaft furnace roasting process. On the basis of Northeastern University "985 Project" Process Industry Integrated Automation Technological Creativity Platform, the software system for optimization control of shaft furnace roasting process is designed and developed. The details are as follows:(1) The existing optimization control approach of shaft furnace roasting process is summarized, including production target coordinated optimization method, pre-set method, forward-feed compensation, feedback compensation and abnormal work-condition diagnosis and fault-tolerant control method.(2) The software system for optimization control of shaft furnace roasting process is designed, where the abnormal work-condition diagnosis and fault-tolerant control module is designed with emphasis. Two layered optimization control structure is introduced, whose objective is First Overflow Recovery Rate. The setpoints of control loops are given by setting model, forward-feed compensator, feedback compensator, prediction model and abnormal work-condition diagnosis and fault-tolerant control module. By this way optimization control of shaft furnace roasting process in normal and abnormal work-conditions is realized. The proposed module diagnoses the imminent abnormal work-conditions, and then the fault-tolerance controller adjusts the setpoints of the control loops. The output of the lower level control system tracks the modified setpoints, which makes the process deviating from abnormal work-conditions gradually with an acceptable production quality.(3) On the basis of Windows2000, the software system for optimization control of shaft furnace roasting process is developed with RsView32, Visual Basic 6.0 and SQL Server2000. The abnormal work-condition diagnosis and fault-tolerant control module is developed with emphasis, in which the expert system for abnormal work-condition diagnosis (AWCDES) and the CBR-based fault-tolerant controller (FTC) is developed.(4) Based on the simulation experiment system for intelligent optimization control of the shaft furnace roasting process, the two experiments of the software system are designed and developed. One is normal work-condition experiment. Another is abnormal work-condition experiment. By those experiments, the software system is valid and feasible.