Iron Ore, Thermal Properties Measurement And Control System Design

In view of the situation that the measuring system for thermal properties of iron ore is relatively backward, this paper discusses a distributed control system based on Industrial Ethernet, which could be used for the synthetic test and process control of iron ore's thermal properties. The research of iron ore's thermal properties can provide the scientific basis for the furnace charge allocated proportion and have the vital practical significance to the blast furnace production.The hierarchical control mode is combined with Industrial Ethernet in the distributed control system for thermal properties of iron ore. The system can be divided into three levels, namely, Industrial Computer, PLC and intelligent instruments. The communication between PLC and Industrial Computer is based on Industrial Ethernet. The application of intelligent instruments improves the control precision and reliability of the system. The monitoring software is based on the Delphi 7.0 programming environment development. Its functions are as follows: communication with intelligent instruments and PLC, real-time process control, data display, data management, real-time characteristic curve plot, data sheet print, information dispatch, and so on.The control of reductive gas ingredient is achieved by means of controlling the temperature of gas producer furnace. It's a key point in the distributed control system for thermal properties of iron ore. The gas producer furnace has some features such as large time-delay, nonlinearity and difficulties of process modeling. It's difficult to achieve the expecting control effect by means of traditional algorithm. Taking the reductive gas production into account, this paper has designed the temperature fuzzy expert control system of gas producer furnace. According to the expert experience and the process parameters, the target value of the gas producer furnace can be properly regulated. This paper has designed the temperature fuzzy adaptive PID controller. Based on STEP-7 and SIEMENS S7-200 PLC, the temperature fuzzy adaptive PID control algorithm has been realized. The simulation result has proved that this control algorithm is feasible. The temperature fuzzy expert control system of gas producer furnace has been put into use. The system obtains a good performance.