Online Monitor and Control of Cooling Temperature on Run-out Table of Hot Strip Mill

At present, adjusting mill velocity is usually applied to guarantee the control precision of finishing temperature FDT for many hot plants, so the forecast of strip velocity progression is frequently not realized as a result of current production conditions. It is difficult to eliminate the strip velocity fluctuation effect on cooling temperature for run-out table cooling control system. In order to improve control precision of cooling temperature on run-out table, the finite-difference model for hot strip cooling process is established basing on Fourier's heat equation. Then taking values easily measured, such as strip finishing temperatures, strip velocity, acceleration rate, value actual on/off status, etc. as auxiliary variables, online monitor function of cooling temperature on run-out table of hot strip mills is developed using soft-sensing technique. With help of this online monitor, twice compensation for strip velocity disturbances is added to run-out table cooling control system. The work in this paper as the matching technology of ultra-fast cooling equipment of Northeastern University of China has been applied to a local 2150 mm hot strip plant successfully.