The Design Of PLC Control System In Annealing Furnace

Wuhu large production line annealing furnace (Abbreviated as large production line annealing furnace)is an important control system of Wuhu steel plant in Anhui. The system is a large-scale PLC control system. There are features of the PLC control system: high level automation , high precision in control ,easy to design ,easy to manage.Whether in checking numbers of connecting points and collecting data or in PLC communication perfectly shows powerful control function of PLC.It's the essential organization that allows the Cast Iron Pipe to gain iron element body. According to the heat-handling skill of the Cast Iron Pipe, the furnace body is designed for four stages: heating, heat preserving, fast cooling, and slow cooling. Through analyzing the properties of the Cast Iron Pipe and the technology of the annealing furnace ,discussing in detail the temperature and pressure parameters of the four sections in the annealing furnace, it chose the excellent annealing technology and proper temperature control curve, got the control base of the annealing furnace.Analyzing the control feature of the system and the temperature and pressure of these four stages as well as the demands of control system and checking numbers, we choose S7-300 Series PLC. PLC system is divided into two: electrical system and meter system. On the basis of systematacially analyzing the craft course, we made use of the king view software to carry on designing and developing the programme of master computer of the system. Ten monitoring pictures are designed ,which can vividly show the system parameter of the annealing furnace and the states of each working point.Aiming at the control task of the annealing furnace,the method of Structured Programming is adopted in designing the program of lower computer.Because of different demands temperature control, and the establishment of different variables has carried on research, We have finished dividing the module and designing program. The system is required to check many data, which are various. Communication is the focal point. We also adopt Ethernet and Profibus on-the- spot. The designed based on the network structure of mixing Ethernet and Profibus on-the-spot .At the time of completing the system hardware to install and correspond by the constitution of network, the fuzzy controller had been studied with emphaisis. After analyzing the general theory of the fuzzy control and its categorize, the fuzzy rule and...