| Iron ore sintering is one of the most important links in integrated steelworks. Along with the rapid development of iron & steel industry in China, technical and economic indexes of iron ore sintering have a direct effect on the economic benefit of steel complex. Thermal state is an important indication of normal sintering process, sintering process in normal thermal state will produce sinter with high grade. At present, thermal state of sintering process is only researched by the indirect judgment of burnt through point or uncontinuous measurement and calculation of sinterbed temperature and quantity of heat. In this paper, side-plate temperature is measured continuously, and software system of thermal state model in sintering process is developed. It has a great theoretical significance and practical use on real-time judgment and analysis of thermal state in sintering process and the guidance of production online.This paper gives a profound analysis of gas-solid heat transfer and physical and chemical change of sintering process, and then thermal state of sintering process is divided into three-dimensions distribution of vertical thermal state, longitudinal thermal state, and transversal thermal state. Take no account of transversal heterogeneity, thermal state of sintering process is described as the change of the thickness of each zone in bed layer and migration rate.Sintering process is divided into three stages and control equations of each stage is set up according to the characteristics of the heat-exchange and chemical reaction of each zone base on heat transfer metallurgical theory, and then the key parameters of equations are calculated. Ideal bed temperature is solved out by the program of implicit difference method. The thickness of each zone and migration rate are also figured out and their thermal state characteristics are analyzed,Non-contact infrared temperature scanner is used in the side-plate vertical temperature measurement of pallet. Filtering process is taken out on raw data using moving-polynomial smoother algorithm. Partition model of each zone is set up by the change characteristics of the curve of side-plate temperature and bed temperature. The bandwidth coefficient of the model is fixed by automatic optimization. The number of side-plate temperature layers is optimized by industrial tests. This research made a deep study of the characteristics of thermal state in sintering process directing at the change of thickness distribution of each zone and migration rate, considering the result of mechanism model. And the thermal state of Bao-Steel under the raw material condition of high limonite proportion is analyzed.According to the data demand of model, the database system SinterDb on the platform of SQL Sever 2000 is designed. Real-time acquisition of data is realized by software communication interface based on OPC technology. Efficient read and write code of data is programmed. The operation of data query is simplified by the use of view mechanism and the safety of data is increased.Software system of thermal state model in sintering process is developed using programming language of VC. Six system functions of vertical thermal state analysis, transversal thermal state analysis, longitudinal thermal state analysis, data query, parameter setting, and system help are realized by multi-thread technology, mixed programming technology of Matcom and VC, and MCI voice technology. This system is put to use. By the guidance of this system in production, it tends towards a reasonable sintering process, and improvement is made in yield and quality. Therefore, the validity of the model is verified. The statistical data shows that the productivity increases 1.23 t/m~2·d, pan yield increases 1.04%, and tumbler strength increases 0.86%. Meanwhile, the economic efficiency increases significantly. According to calculation, the direct economic benefit of this system can reach to 17,000,000 RMB/year. The development of thermal state model based on side-plate temperature measurement and the application of this software system provide a new way in the research of thermal state of sintering process. And it has a bright prospect of application.
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