| At present, to the problem of blast furnace and TRT (Top Gas Pressure Recovery Turbine Unit), the isolated mode of optimization and control is widely applied among Chinese steel enterprises. However, when mineral raw material content fluctuates or other disturbances take place, it is easy to cause the instability of iron-making process, molten iron of low quality and TRT in emergency process, with unnecessary energy cost.This subject is one important part of national key project, whose name is integrated control system for smooth operation and energy saving in iron-making process. The main contents of this thesis are described as follows:1. Establishing the dynamic associated models of blast furnace system and TRTFirst, in terms of the whole of blast furnace and TRT, the overall associated dynamic model framework is built. Mechanism of blast furnace system and TRT is used to build their models. Based on multi-fluid theory and the principle of heat transfer, one-dimensional temperature distribution model of the whole blast furnace system is built to explain the complex control discipline of the temperature of blast furnace, and to predict the temperature of blast furnace.2. A distributed coordinated control algorithm for blast furnace and TRT is proposed.To solve the problem of inter-related coupling characteristics of blast furnace system and TRT, a distributed predictive control algorithm for the coordinated control of blast furnace and TRT is proposed. This algorithm takes advantage of the principle of rolling optimization of predictive control, and feedback correlation is used for reducing the error caused in modeling timely. As a result, this algorithm has better optimizing performance than isolated predictive control, in the guarantee of real-time of computing.3. An improved alterable horizon distributed predictive control algorithm targeted at multi-time-scale is proposed. As blast furnace system and TRT have different dynamic characteristics, there is a multi-time scale problem in the coordinated control of the two systems. An improved alterable horizon distributed predictive control algorithm is raised, which virtually changes the sampling period of fast sub-system, and adds the missing associated information by linear interpolating in the predictive output value, with high accuracy.4. The development and application of blast furnace gas forecasting systemThe output of blast furnace gas is a key factor in the coordinated control of blast furnace system and TRT. A forecasting model of blast furnace gas output based on improved BP network is proposed, which could forecast the trends of blast furnace gas output accurately and has been successfully applied in the gas scheduling system of Hangzhou Iron & Steel Group Company of China. |
