| Blast furnace top gas pressure recovery turbine unit (briefly as TRT unit) drives turbine to generate electricity by making use of pressure potential energy of gas that generated in the blast furnace ironmaking process, which avoids waste of eliminating pressure potential energy through decompression valve group and reduces noise pollution caused by valves group.Therefore, TRT unit is an environment friendly and energy saving equipment of low-input but high-yield. Because the stability of top pressure of the blast furnace is important factor that influence main process of the blast furnace worry about instability caused by TRT unit and the influence onthe product when TRT unit is applied for power generation. Consequently, it is the key that how to keep the stability of the blast furnace top pressure for the technology quality and promotion of TRT.The precondition of applying TRT, an energy recycle device, is the stability of blast furnace's top gas pressure during operation, thus no disturbance will be introduced to the main process. At present, the most popular method to stabilize the top gas pressure is the empirical PID control of the adjustable static blade opening. However, with the large-scale metallurgical blast furnace and the modern development of ironmaking technology, the requirement on top pressure stability becomes higher. And the PID control is difficult to achieve the expected control requirements. Therefore, it is necessary to research the methods of control of top pressure further.The thesis studies the TRT static blade control system and researches the control metheds of blast furnace top pressure. For the characteristics of blast furnace top pressure, analysises the TRT control system to satisfy the closed-loop identifiability conditions in theory and establishes a dynamic mathematical model of blast furnace top pressure in normal operating conditions by the method of combining mechanism analysis and parameter identification. Because there being a variety of disturbances on the blast furnace top pressure in the normal operating conditions, strong anti-interference is used to design the IMC controller with two degrees of freedom for the blast furnace top pressure in order to improve the robustness of the blast furnace top pressure control. On the basis of the IMC designing and the analysis of electro-hydraulic servo system which is an executive body of the blast furnace top pressure, the purpose of TRT control is completed and a new control approach for the blast furnace top pressure of the TRT system in normal conditions is provided. |
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