Liangang Coke Oven Heating Combustion Process Control System Design And Its Application

Coke oven is a complex plant with the characteristics of large time-delay, strong non-linear, multivariable coupling and changeable parameter. The coke oven flow temperature is one of the critical technical parameters in the course of the coke oven heating combustion. The coke oven flow temperature is tightly connected with the output and quality of the product, as well as the life-span of the oven.In the view of coke oven heating combustion process mechanism, this control system structure was put forward based on system needs and introduce the system course. The control system includes obtaining process parameters, monitoring heating, gas pressure control loop, the sub flue suction control loop and the temperature control loop.The heating process for coke oven is of complexity and there are many parameters need to monitor. Siemens S7-400 PLC is used to measure these parameters including temperature, gas flue and gas pressure. WinCC control system is used to supervise information and heating process. Because it is very difficult to measure the flue temperature directly, the soft-sensing model of flue temperature is build. According to the error of the flue temperature, fuzzy-expert strategy is used to regulate the setting values of gas and air, so the temperature control loop is structured. In order to maintain the flue temperature and guarantee the gas can combustion fully, gas pressure control loop and the sub flue suction control loop are designed.The paper also discuss the control system realization, including process configuration realization and process realization. The data communication methods between the PLC system and WinCC system, also between WinCC system and control software, were also discussed. The configuration of control system was completed by use of WinCC and control software was implemented with the VC++ language and the block programming. The application software communicated with the configure software with help of the OPC technology.The control system has been applied in the factory. The result of real-time control shows the system is advanced and accord with industrial fact. The system has a great significe to improve the quality of the coke, reduce energy consumption and prolong the service life of oven body. At the same time, the system creates huge economic and social benefit.