Study On Control System For Hot Oil Furnace Based On Fuzzy Control Theory

The energy shortage and the atmospheric pollution are the two difficult problems confronting every country in the modern world. And with the rapid development of the industry in our country these problems become worse, hence how to resolve them becomes more and more important factor to influence us to realize the strategy of sustainable development.The hot oil furnace system is a complex time-varying and dynamic process with multi-variable, strong coupling, nonlinearity and large lag like other general industrial boiler. As it's hard to achieve satisfying control performances with conventional PID control algorithms, which leads to the low combustion efficiency, high energy consumption, combustion instability, and unacceptable smoke emission. So it is of profound practical significance to control the combustion process of the hot oil furnace system in order to run the boiler stably with high efficiency, low energy wastage and acceptable smoke emission standard. It is most important for the combustion with high efficiency and stability in the combustion process of hot oil furnace to control the air/fuel ratio. In the thesis we studied the air/fuel ratio control of the combustion control system in Jinan Zhenghao Advanced Fibre Co., Ltd. As it has a good dynamic and static performance — prompt dynamic response without static error, the PID fuzzy controller with variable structure improved evidently the combustion efficiency and made combustion more efficient and stable. Furthermore, the controller is of great practical value in construction project because it can be used easily in PLC.The system structure based on IPC+PLC makes the control system more advanced and reliable, hence it is easy for it to be installed, used, expanded its function and updated of system, which makes it conform to the trend of standardization, and modularization in modern industry, adapt to the intellectualized, networked and integrated trend of modern industry control. Therefore the controller, which realized the centralized display and operation of different working parameters adopting PLC, raised our efficiency in operation and management.Besides the above, we used frequency converter to control the air flows of air-blower, and achieved a good energy-saving effect.