Application And Research On Integrated Management And Control System Of Steel Ladle In The Second Steelmaking Plant Of Qiangang

The entire turnover process of steel ladle in the second steelmaking plant of Qiangang has been systemically analysed in the dissertation, basing on the theory of dynamic operation from metallurgical process engineering. And some key problems and technical difficulties have been studied. On the basis of analyzing the parameters such as the time of turnover ladles, the turnover rate of steel ladles and the tapping temperature of molten steel, the static calculation for the turnover number of steel ladles, the dynamic modeling and simulation of steel ladle turnover process, the optimization of steel ladle turnover process and the development of integrated management and control system of steel ladle were all studied.First and foremost, the relationship between the production rhythm of Furnace-Caster and the number of turnover ladles was analyzed by using Gantt chart, basing on the Furnace-Caster matching principle. And the calculation model for the number of turnover ladles was given according to the existing modes of Furnace-Caster matching in the steelmaking plant. The results show that the number of turnover ladles can be reduced by decreasing the flexible time of turnover ladles and the overlap time between casting heats.Besides, a simulation model of steel ladle turnover process was constructed, according to the production flow of the second steelmaking plant.of Qiangang. In the model, the time fluctuation and constraint rules were taken into account. Some affecting factors on the turnover rate of steel ladles and the rate of hot steel ladles were studied such as the hot repair time, by inputting the actual production schedule. Simulation results show that both the turnover rate of steel ladles and the rate of hot steel ladles gradually decrease with the hot repair time increasing. When the daily productivity of typical steel is45heats, the turnover rate is6.43with the hot repair time from0to20min, but the turnover rate is5.00with the hot repair time from50to60min. At the same time, the rate of hot steel ladles drops from94%to45%with the increasing of hot repair time.And then, the optimization problem for the turnover process of steel ladle can be seen as Job Shop Problem. The mathematical model was established to minimize the time of turnover ladles and the overlap time between casting heats. The turnover process of steel ladles was effectively optimized by the scheduling plan which was solved by the improved genetic algorithm. When the daily productivity of typical steel is43heats, the time of turnover ladles is shortened664min, and the overlap time between casting heats is cut down14min. Moreover, the turnover rate of steel ladles increases0.48, and the rate of hot steel ladles raises up to67.4%.In the end, the integrated management and control system of steel ladle was developed in view of the common problems of steel ladle management and control. Collecting and sharing the information of steel ladle in the plant was not only realized, but also the function of steel ladle tracking, steel ladle matching and the temperature compensation of molten steel were achieved. After the application of the system, the backward model of steel ladle artificial scheduling was changed. What is more, the system played an important role in increasing the turnover rate of steel ladles, lowering the tapping temperature of molten steel and saving steelmaking energy.