Blast furnace process automation is generally equipped with two levels of automation control system for the blast furnace: Level I is the basic automation system, Level II is the process computer system.
The basic automation system consists of electrical transmission and control automation and process detection& control automation system, and its main functions are data acquisition, sequence control, continuous control, monitoring operation, HMI and data communication (including accepting the set values from the process automation system and sending the actual process data to the process automation system) for the production process. The operator can modify process parameters and change the operating status of equipment, and monitor the entire production process.
The basic automation system consists of controllers, HMI (human-machine interface), control software and its related industrial Ethernet network. At the same time, it provides network interface with the process computer system and the superior basic automation control system.
Varying number of controllers and HMIs according to the process requirements are equipped to related processes like raw material supply, bell-less furnace top and coarse gas dedusting, blast furnace body and its water cooling, hot blast furnace, iron tapping yard, slag treatment, coal injection and gas purification system, TRT, soft/clean circulating water treatment, blower station, and so on
Main screens of basic automation operation station: dynamic process flow diagram and operation screen; control loop display screen (including bar graphs and numerical displays of set values, process variables and output values); operation panels of various types of equipments; trend curves (real-time and historical); alarm screen: the screen can be printed out according to the need for analysis by technicians; system diagnostic screen including unit, network and module status.
The main functions of the process automation system include process technology calculation, mathematical modeling, production guidance, process monitoring, data communication and production reports, etc. Network communication is adopted between Level I and Level II systems, and the Level II system contains a communication interface with the plant-level management computer system.
Mathematical models generally include furnace charge optimization, material balance, no material bell roof charge, furnace charging simulation, indirect reduction, tuyere area calculation, theoretical flame temperature, soft melting zone, furnace hearth balance mode, furnace bottom erosion, iron temperature forecast, iron Si content forecast, hot stove combustion control, air supply simulation and blast kinetic energy model.
The process computer calculates and stores the actual process data (including material and energy medium consumption ) in shifts, daily averages and cumulative values. The data in the database can be easily retrieved, queried and counted for historical data, and production reports can be printed.
More and more ironmaking enterprises apply blast furnace expert system, through the blast furnace thermal state system, operation management, furnace diagnosis and furnace balance management, coke ratio control, furnace alkalinity control and blowing amount control, forecasting molten iron temperature, calculating slag and iron level height in the cylinder, etc., and integrating the cutting-edge technologies such as cloud computing, Internet of Things, big data, artificial intelligence and mobile Internet, the production of blast furnace will be more and more efficient, green and safe.
