| Blast furnace(BF)ironmaking process is very important to iron and steel industry,which has many advantages,such as relatively simple process,large production and high productivity,that lead it to be the main way of modern ironmaking production in the world.There are about 95%of the world's pig-iron production to be produced by BF.In order to keep long-term safety production and get full use of the discharge slag-iron,foreman of BF needs to know the production situation in real time and timely adjust operation systems,such as burden distribution system,thermal system,etc.It is necessary to monitor and control BF timely for achieving the goal of high quality,high yield,low consumption and long life during the production.However,the internal environment of BF is extremely harsh:its temperature is over 2000? while the pressure is about 4 times of the standard atmosphere.Moreover,there is a hybrid state of coexistence of solid,liquid and gas phases inside of BF.So,its hard to realize operation control and optimization of BF ironmaking process.In addition,blast furnace operation implements are still based on the experience and intuition of skilled operators today,which is limited to the detection and control technology.Compared to the developed countries,our country's level of automation in blast furnace ironmaking process is low.Only few relevant industrial control software has been developed and applied in iron and steel industry.Nowadays,many kinds of software,such as monitor software,diagnostic software of molten iron quality(MIQ)have been developed,but there are no reports reported about the operational optimal control software of MIQ currently.Considering these problems,this paper carries out research on designing and developing a software about MIQ operational optimal control in BF ironmaking process and conducts experiments on 2#blast furnace of Liuzhou Iron and Steel Company in Guangxi province with the support of National Natural Science Foundations,"High-performance operation control and implement technology of large blast furnace"(Item number:61290323)and "Experimental verification platform construction and application verification of large blast furnace high-performance operation control"(Item number:61290321).The specific works are as follows:(1)First of all,this paper gives a detailed analysis of the current research of the development of the operational optimal control software in BF ironmaking process and other industrial fields.Then,significance of developing the software of operational optimal control of MIQ is given.Next,the requirements of developing the software have been analyzed and discussed,which include functional requirements,performance requirements and operation requirements.(2)According to the requirement analyses,the control strategy and algorithm about the operational optimal control of MIQ have been researched,which mainly include the loop setting module of control variables based on rule-based reasoning(RBR)and case-based reasoning(CRB)mixed reasoning algorithm,the prediction module of the online subspace input-output model for predicting MIQ indices and the model predictive control(MPC)module based on the subspace estimator.The loop setting module is used to provide the optimized setting points for basic loop control variables,such as pressure of hot air,blast humidity,temperature of hot air and so on,according to the predictive values of the Si content([Si])and the molten iron temperature(MIT)based on RBR and CBR mixed reasoning technology.Prediction model is used to predict[Si]and MIT on line.The control module is mainly based on model predictive control algorithm,which can compensate for these control variables in the last sampling moment by minimizing the deviations between the predictions and the expectations of MIQ.(3)After the completion of theoretical research,the 2#blast furnace of Liuzhou Iron and Steel Company is taken as an application object to develop the software.Combining with these above research theories,this paper has proposed a three layers structure development mode of client and server based on.NET platform.The structure and functional modules of the software have been designed and developed.Functional modules mainly include MIQ control functional module,man-machine interaction module and database module.C#is chosen as the programming language to develop the software with the object-oriented thought.The common parts in the code are designed to be classes in order to reduce the workload of software developing and optimize the structure of program.The system uses SQL Server database as back-end database in order to be consistent with the field's.The front ground is mainly for the design of the customer interface and it makes use of the SQL.User interfaces are designed in the form of winform and all of these interfaces would be integrated into the main interface for reducing the number of popovers,so it's very convenient to operate the software.(4)After the work of developing the software is completed,industrial experiment of the software in blast furnace ironmaking process has been conducted in 2#blast funace of Liuzhou Iron and Steel Company in Guangxi province,and the software testing is mainly about MIQ prediction function.Field data will be preprocessed at first for modeling before using for the model's input,and the output data can be used for real-time display and storage.Prediction model can be retrained online if necessary.Test results and the reporting of the field workers show that the system software has many advantages,such as nice and neat user interfaces,stable and seamless working performance and easy operation.This software can help the blast furnace operators a lot. |
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