Influence of Accelerating Rolling on the Laminar Cooling Exit Temperature in Hot Strip Mill

The principle of heat transfer is adopted for the strip temperature finite difference model and the heat transfer coefficient of water is amended based on measured data.The temperature change is numerically simulated in the process of Desheng 1 150 mm hot strip laminar cooling.The simulation system is established to study the change trend of laminar cooling temperature in accelerating rolling.Resultsshow that the coil temperature is significantly influenced by the speed of strip,the strip temperature gradually increases from the front to the back,and the temperature deviation increases with the acceleration without dynamic regulation of the cooling pipe system during acceleration.Based on the conclusions,the L₂-level hardware is a process server,the L₁-level hardware is Siemens PLC for the online control system and the softwares of L₁ and L₂ are programmed by C++ and Step7V54.The successful control strategy online tracking of head and tail of the hot strip in the basic automation and the elements micro-tracking in process automation are introduced,variable motion of the strip is controlled along the length point by point,and dynamic regulation of the cooling pipe system is used to ensure the stability of coiling temperature during the change in speed.