Research And Application Of Laminar Cooling Control System In Hot Strip Mill

Control cooling in hot rolling mill is a very important method to control and improve the quality of product. Laminar cooling control is one of control cooling, and coiling temperature is one important parameter of performance of hot strip. With the laminar cooling system of our country as the background, this dissertation studies the laminar cooling computer control system.theory models such as heat transfer mechanism models, mathematical model (mainly includes the temperature drop calculation model?feedback calculation model?self-learning model) and so on, were systematically researched. The overall function of the laminar cooling system model and the cooling strategies were detailed introduced,and in-depth analysis the control function of the functional modules in the laminar cooling system. The effect of rolling speed on run-out table cooling was studied and feedforward control algorithm was designed for non-constant speed rolling.In view of the influence of latent heat on the strip steel cooling process and the hysteresis quality consist in the conventional feedback control, optimizing some relevant models to improve the control precision. The main research contents and achievements are as follows:(1) Theoretical models of run-out table cooling were researched deeply. According to the basic heat transfer theory, analysis the temperature drop calculation model?feedback calculation model?self-learning model of a domestic hot rolling mill.(2) The function modules of the cooling control system such as pre-setup calculation, modification setup calculation, feedback control, and self-learning were researched in detail in the paper, the algorithm process and procedure of each control modules were described.(3) Rolling speed and its effect on run-out table cooling were studied, the strip sample tracking method was described and high-precision feedforward control algorithm was designed.(4) In view of the influence of latent heat on the strip steel cooling process and the hysteresis quality consist in the conventional feedback control, optimizing some relevant models, coiling temperature control precision were further improved after optimized.