Research on converter steelmaking based on automatic control technology

　　Abstract: converter steelmaking is a vital production technology in the process of steel production. This paper first analyzes the automatic control technology and process flow of converter steelmaking, and then analyzes the problems and measures of converter steelmaking automatic control, aiming to improve the steel production quality of domestic steel enterprises and promote the better development of the steel industry.

　　Key words: steel; Converter steelmaking; Automatic control; technological process

　　Nowadays, the innovation speed of industrial production technology is accelerating, and the application of automation technology is becoming more and more extensive. The application of automation technology has promoted the development and innovation of steel-making technology in China, further improved the efficiency of steel production, and made great contributions to the ecological environment. In the new era, iron and steel automation technology has developed rapidly. If iron and steel enterprises want to adapt to the development of the times, they need to improve their production efficiency and production level. Therefore, iron and steel enterprises need to invest more money in the research of automatic control technology, effectively use computer technology in production, reduce manual extensive production, minimize physical consumption, and promote the automation and modernization of iron and steel production.
 

　　1. Analysis of automatic control technology for converter steelmaking

　　1.1 basic principles

　　The automatic control technology of converter steelmaking technology includes computer information network technology, industrial control technology and detection technology. In the past, molten iron, ferroalloy and scrap iron were the main raw materials for steelmaking. Under the action of high temperature, chemical reaction is formed and combined to produce steel. The automatic control technology of converter steelmaking is based on the computer to analyze the above raw material data, so as to calculate the steel type to be manufactured, the required solvent addition amount, oxygen lance blowing height, bottom blowing amount, oxygen blowing amount and other data, and then detect the temperature and composition of molten steel again in the later stage of blowing. After obtaining the data, through the cooperation of various system settings, the automatic control technology is used to make steel to ensure that the expected goal is achieved, Obtain high-quality and high-quality steel.

　　1.2 basic operation contents

　　The primary work of converter steelmaking automation control is to pretreat the molten iron provided by the ironmaking plant, then smelt and process the pretreated molten iron, and finally process it into steel. This process includes the oxidation of molten iron and the removal of impurities to ensure the purity of molten iron components. After that, a specific amount of lime is added to form oxidizing slag. After heating to a certain temperature, oxidant and alloy raw materials are added to form steel materials. In adopting automatic control technology, it is necessary to cooperate with computers and control equipment, strictly control the operation progress and process, and pay attention to slag blocking during tapping, which will have a direct impact on the quality and quality of steel.
 

　　2. Classification of automatic control technology for converter steelmaking

　　In recent years, China's steel output has always ranked first in the world. According to data, China's total steel output in 2020 was 1.065 billion tons, accounting for 57.1% of the global steel output, which is more than ten times that of India, the second and Japan, the third. In 2019, China produced 996million tons of crude steel, accounting for 53.31% of the total global production, which is enough to reflect the major changes in the development of China's steel industry. With the continuous development of society, various advanced technologies have been widely used in various fields. The following mainly analyzes the classification of converter steelmaking automation control technology.

　　2.1 converter steelmaking detection technology

　　In fact, the detection technology of converter steelmaking is to detect the process of converter steelmaking. Many instruments and meters are installed in the converter, which can collect the temperature, composition and molten steel information in the converter. The workers recorded the parameters of the instruments and meters, and analyzed the data of the converter instruments in real time with the detection technology, which provided some data support for the automatic control of the converter steelmaking. As the basis of automatic control of converter steelmaking, instruments and meters detect the whole process of automatic steelmaking, which can avoid the problems and deficiencies in the automatic control process of converter steelmaking.

　　2.2 automatic control technology

　　Automatic control technology is formed based on information technology. With the advantage of accuracy and convenience of computer network, it improves efficiency, finds out the problems in converter steelmaking in time, and carries out intelligent control, which greatly improves the quality of steel. The automatic control technology of converter steelmaking includes two kinds: dynamic control model and feedback calculation model. Because the two technologies have different functions, the contents detected in converter steelmaking are also different. The dynamic control model is more about monitoring the oxygen and coolant content in converter steelmaking to see whether the content meets the requirements, and timely adjusting the carbon content and temperature in converter steelmaking. The feedback calculation model mainly monitors the dynamic control model. If there is a problem with the monitoring of the dynamic control model or the data, the feedback calculation model will be adjusted in time to minimize the error or prevent the error. The dynamic control model and feedback calculation model cooperate with each other to meet the technical requirements of automatic control. The adoption of automatic control technology saves the cost of human resources to a certain extent, prevents the waste of raw materials, improves the accuracy of control, and fully reflects the advantages of modernization and information development.

　　2.3 exhaust gas analysis and detection technology

　　Nowadays, in the automatic control technology of converter steelmaking, the exhaust gas detection technology of furnace carbon determination method is mainly used. The detection enterprises are mainly converter exhaust gas in converter equipment, which has strong toxicity and seriously endangers the environment, so it needs to be detected and treated. In the detection process, nitrogen and carbon removal should be carried out during the calculation and treatment of waste gas, so as to determine whether there is a large amount of carbon content in the converter. The carbon content of molten steel and automatic detection of molten steel composition can be reflected in real time through these monitoring information.

　　2.4 combination of furnace gas carbon determination and auxiliary gun

　　The combination of furnace gas carbon determination and auxiliary gun can also be used for waste gas calculation, focusing on the calculation of decarburization speed in the process of converter steelmaking, so as to master the automation state of converter steelmaking. According to the technology mainly based on the auxiliary gun, the furnace gas carbon determination method plays a secondary role. The specific content of residual carbon in the converter is calculated to clarify the carbon content in the converter. The combination of furnace gas carbon determination and auxiliary gun technology helps to improve the accuracy and speed of calculation, so as to improve the carbon content of converter, provide corresponding data support for automatic control production, and promote the automatic control of converter steelmaking to be more effective.

　　2.5 mathematical model technology

　　Both static control and dynamic real-time control of automatic control in the furnace are based on mathematical analysis, especially according to the analysis and calculation process of the established mathematical model, so as to clarify the subtle changes of chemical reactions in the internal chemical balance equation of the furnace. The mathematical model calculation can understand the change of oxygen content in the furnace and the temperature change of the oxygen gun, so that the technicians can estimate the operation of the tempering program, and analyze and adjust it in combination with the information and data parameters fed back by the auxiliary gun, so as to ensure the smooth progress of automatic control in the furnace.

　　2.6 artificial intelligence

　　With the rapid popularization of artificial intelligence technology, many large-scale factory equipment began to expand the scope of the use of artificial intelligence. Using artificial intelligence in the automatic control equipment of converter steelmaking can greatly improve the overall automation efficiency of the equipment and reduce the situation of human error. The extensive use of artificial intelligence technology and the automatic control technology of converter steelmaking can promote the double improvement of efficiency and quality, and the double control of output and cost, which is conducive to the further development of iron and steel enterprises.

　　2.7 image processing and judgment Technology

　　Image processing judgment technology is similar to spectral optical judgment technology, which is a non-contact measurement technology. This technology is mainly used to monitor the changes of converter mouth flame in real time, so as to collect useful potential information. The collection of information is mainly realized by analyzing texture, extracting features, color model conversion, etc. the information is related to the steelmaking process and flame pattern, and then the system modeling is carried out after the potential information is collected, so as to predict and judge the end point.

　　2.8 intelligent terminal control technology

　　Neural network and expert system are the representatives of this technology. This technology mainly focuses on the basis of converter steelmaking process, focuses on optimizing and controlling the steelmaking process, and changes the previous working method of pursuing the deep law of steelmaking process. Therefore, this technology has been widely promoted in specific work. Many domestic steel enterprises have adopted neural network technology in converter steelmaking automation control, but Japan and South Korea are in a relatively leading position. In general, these technologies mainly investigate the input and output, reduce the random error to a certain extent, and ensure that the accuracy can meet the requirements, which has extremely significant advantages.
 

　　3. Process flow analysis of converter steelmaking automation control technology

　　3.1 oxygen supply system

　　The oxygen supply system can control the position and amount of oxygen supply, collect data according to the calculation model and carry out dynamic control. The position of the oxygen lance can be changed at will, and the oxygen supply at a specific position can be adjusted in combination with the feedback data, so as to reduce the oxygen content and improve the purity of steel. This system can collect data, effectively improve the oxygen blowing rate and reasonably control the gap with the liquid steel level by connecting the set program.

　　3.2 raw material system

　　This system can weigh molten iron, scrap steel, ferroalloy and other raw materials, use professional equipment to change the proportion, and complete the peeling and weighing of molten iron at the same time. After weighing, dynamic proportioning of ingredients is carried out based on this program, and the proportioning of raw materials is controlled until the best proportioning is achieved. Because raw materials come from a wide range of sources, it is necessary to control the physical heat of molten iron and the chemical reaction between its components through the data model of reducing energy consumption.

　　3.3 auxiliary gun system

　　Due to the continuous improvement of automation, the auxiliary gun system is widely used in the steel production industry. The secondary gun system has a high degree of automation, which can better detect the carbon content and temperature of molten steel, and compare it with the corresponding standards. The sub gun system can use the sub gun probe, extend the probe into the molten steel, collect real-time data, and transmit the data results to the computer, so as to provide some data support for the construction of the data model.

　　3.4 exhaust gas measurement system

　　When steelmaking, a certain amount of waste gas will be formed. Usually, the waste gas is mainly composed of carbon dioxide and carbon monoxide. In order to effectively control the content of waste gas, a waste gas composition monitoring system should be installed in the converter to effectively monitor the concentration of waste gas, so as to accurately evaluate the concentration of carbon content in molten steel in the converter. At the same time, based on this, combined with the data collected by the sub gun system, various production indicators in the converter should be effectively monitored, so as to improve the quality of steel production in an all-round way.
 

　　4. Common problems and Countermeasures in automatic control technology of converter steelmaking

　　4.1 opening and tripping

　　Opening trip is usually related to frequency converter. To solve this problem, personnel are required to detect whether there is a problem with the frequency converter. Once there is a poor closing contact problem, attention should be paid to the inspection of the frequency converter. The staff should also calculate the operating position deviation and control the output parameters, usually at zero, so as to realize the closing operation. The detection of opening and tripping problems not only requires the staff to have rich professional knowledge and can quickly find the instruments with problems, but also requires the implementation of professional methods to prevent the failure from bringing adverse effects to the whole production line.

　　4.2 signal transmission problems

　　The operation of automatic control system should be supported by stable signal transmission. If the system communication is disconnected or the signal is interfered, the actuator will malfunction or not act, and the display unit may misdisplay or not display, resulting in unpredictable consequences. If the screen display is wrong or the displayed data is obviously abnormal, it can be judged as a system communication failure. In this regard, you should first check the relevant signal indicators, and then check whether the network communication line is in good contact or interrupted, and whether the switch interface is disconnected by shrapnel.

　　4.3 abnormal problems of shaking furnace

　　The furnace shaking control needs to rely on the assistance of the electrical system. Under the condition of normal power on and stable operation of the electrical system, if the furnace shaking has abnormal problems or cannot be shaken, it is necessary to detect whether the oxygen gun position and lubrication temperature are normal. Once the shaking is abnormal or the automatic control system has problems, the high-temperature liquid steel in the converter will cause damage to the converter, and once the liquid steel overflows, it will also cause production accidents. When the above problems occur, it is necessary to immediately implement countermeasures and implement the enforcement mode to forcibly control the converter. In this mode, the main control console is connected to the shaking furnace by a special line, and the corresponding buttons are installed on the operation console, so that it will not be affected by the automation system and other lines, so as to ensure the stability of operation.

　　4.4 raise questions about oxygen lance

　　This problem is generally caused by abnormal changes in refrigerant flow. If the refrigerant flow is lower than the standard value, the oxygen lance will be lifted. In addition, the lifting and position change of the oxygen lance are mostly carried out by the power system, so if the oxygen lance cannot be lifted and automatically lifted, after excluding the influence of production process and control system factors, we should consider whether there is a problem in the electrical system of the oxygen lance.
 

　　5. Conclusion

　　To sum up, facing the current national standards, there are many difficulties in the steel-making industry. The environment of converter steel-making industry is relatively poor, and the operation process is relatively complex, which has high requirements for the precision of technology. Only by relying on advanced science and technology and promoting the automatic control technology of converter steelmaking can we alleviate the difficulties faced by the steelmaking industry. By meeting the above requirements, we can ensure the production of high-quality steel products and bring higher benefits to steel-making enterprises. It can be said that this technology has played an important role in promoting iron and steel enterprises and further optimized the industrial production structure. It is believed that this artificial intelligence technology will be more widely used in the future.