Study And Application Of The Pulse Combustion Fuzzy Control Technology With Variable Cycle Period

Reheating furnace is an important thermal equipment of Steel mills, its main task is to heat the billet steel to the rolling needed process requirement for enhancing the plasticity of the billet steel and reducing its deformation resistance. Reheating furnace is always the energy hog among the equipment of steel mills, but one of the big problems is that the energy shortage of our country which constrained the economic sustainable development. The main research content of this paper:on the basis of ensuring the heating quality and production efficiency of the billet steel, enabling the automatic control system to reduce the energy consumption of the reheating furnace and ensure the best burning of combustion system, and then reduce the pollution degree to the environment accordingly.The burning process and heat-transfer mechanism of reheating furnace is very complicated, and it is very difficult for modeling. Using the traditional control mode can’t control the furnace temperature and heating process accurately and effectively, and the high energy consumption of the reheating furnace also can’t be resolved. Moreover, for the regenerative reheating furnace, its energy saving mainly relies on the heat storage of the regenerator, so it is impossible to save the energy if the heat storage efficiency is not the best. Therefore, this paper summarizes the temperature control technology of the reheating furnace and the application status home and abroad, and works out the best time for heat storage of the regenerator. In order to make the heat storage time in each commutation cycle of the burner to be the best, we combined the theory of fuzzy control with the technology of variable cycle pulse combustion control, and proposed a furnace temperature fuzzy control strategy of variable cycle pulse combustion furnace, and put this to use on the control of the furnace temperature.The mainly contents of this paper are as follows:the components and operating principle of the burning system for reheating furnace, analysis of several factors that influences the furnace temperature in detail, as well as various reasons which result in energy waste of the reheating furnace, and proposes the corresponding countermeasures accordingly; analyzes the feature and components of fuzzy control; confirms the structure of the reheating furnace’s PLC control system against the features of each sensor and actuator at the worksite, and the type selection of the development software and hardware of the system according to its needs; analyzes the characteristics of the controlled objects and the basic control process of reheating furnace, designs complete in the master-slave PLC communication mode and structure, and plans the programs in CPU reasonably; For the heat balance theory of the reheating furnace temperature and the high energy consumption, through comparing with the traditional continuous thermostatic and the fixed cycle pulse combustion control technology, we propose the variable cycle pulse combustion control theory, combining with the fuzzy control, and design the appropriate PLC for field application. It is proved through practice that this system meets the technological requirements of energy saving, the combustion conditions of the reheating furnace is good as well as the operation is stable and reliable.