Automatic Control System In Hot-Blast Stove Based On PLC

Ball-style hot-blast stove is one of the important equipment of iron-smelting. In recent years, it has been developing continuously with high winds, save investment, and easy maintenance advantages in China's medium-furnace. Hot-blast stove wind level control has also increased significantly, which has very important impact and significance for blast furnace smelting.This thesis is the construct engineering of 4 ball-style hot-blast stoves of 5# 508 m3 (the following abbreviation 5# stove) in jiyuan STEEL&IRON Co. in Henan. Combining the control requirements of ball-style hot-blast stove with the technological craft process of 5# hot-blast stove, the thesis proposes and completes the overall plan of the control system. By analyzing control points on spot, the process control station and the long-distance control station has selected Siemens S7414-2DP and the related module. In view of the characteristics of temperature's dynamic change in combustion process and difficulty in realizing real-time control, the thesis studies the system control method with emphasis. Based on analyzing the general theory of the fuzzy control and its categorize, the design of fuzzy controller about the best ratio of air to fuel ambiguous is completed by the serial process of constructing the fuzzy rule and its control watch and the process of anti- faintnesses etc. It is contrasted with the PID control by experiment.According to the claim of the hot-blast furnace to monitor system, the computer control system is designed. With WinCC6.0 for the development software, configure monitor and control menu is designed, corresponding monitor program is worked out. Which makes the system process has such functions as dynamic monitor, archive history data, singularity alarm, locale handling supervise and control of production process.Through the analysis of entire craft process and the control request, programming software Step7 is adopted. The complex automated duty was decomposed into the independent function block. When executed by the main loop module, to make control easier.Combining the actual circumstance of 5# hot-blast stove, while designing the communication project, 5 ET200M long-distance control stations composed by the industrial ether net and the Profibus-DP to construct a two layers of network system.