Research And Application On Electrode Control Of LF Ladle Refining Furnace

Refining technology outside of the furnace is increasingly becoming the new darling of the steel industry in the world due to its advantages of improving steel quality and production, reducing costs, improving working and environmental conditions. LF ladle refining furnace is typical refining technology equipment which is widely used, for its excellent metallurgical properties, low equipment cost and easy operation. The electrode regulator is an important equipment of refining furnace. In the refining process, the location of the electrode affects the important indicator of LF directly and the electrode regulator is the heart of LF refining furnace control system. The study on the electrode control of LF is significant, which can achieve the precise and effective control to the temperature and composition of steel furnace.The background of the paper is LF furnace and the object of the study is the electrode regulator. On the basis of mastering the basic process of LF refining, especially the LF furnace electrode structure and working principle, the thesis analyzes the characteristics of the arc between the electrodes and how to choose the reasonable electrical operating point. In order to design the electrode control system, the mathematical models for LF furnace electrode electrical system and the hydraulic drive system are created and analyzed. Then through comparing several popular control methods of electrode regulator, the constant impedance adjustment method is selected as a more appropriate one and the control system of it is analyzed then. Because the electrode control system is a multivariable and strong coupling system. If using conventional PID control, the result is not satisfactory and it could lead to electrode instability, the increasing of grid electricity consumption and the fluctuations of voltage. Therefore, the artificial neural network control method is proposed and the neural control algorithm is combined with the PID. Neuron PID algorithm is used to design the electrode regulator to improve the performance of LF furnace electrode control and then to improve steel quality and reduce tons of steel consumption.Finally, the author compares and analyzes the two of LF furnace electrode regulators in Benxi Iron and Steel Plant. One is DANIELI electrode regulator based on PID control and the other is a smart electrode regulator based on artificial neural network control. By the comparison we can see the intelligent electrode regulator using Neuron PID algorithm PID control is better than the one using PID only. The electrode regulator control system based on the artificial neural network has better stability, higher control accuracy and satisfactory result.