CAJ | 학술논문

针对因变速轧制和复合冷却带来的卷取温度模型预报精度降低的问题，以热输出辊道上的冷却设备布置信息和辊间冷却换热形式为出发点，采用Crank-Nicolson( C-N)六点格式有限差分方法构建轧件轧后冷却温度计算模型；以前馈为主、反馈为辅，不断进行自学习来对轧件冷却温度进行控制，在精轧出口按照固定时间周期对轧件进行分段采样和前馈设定，在卷取入口按照长度进行分段采样和周期性反馈控制；为使模型适应升速轧制和因终轧温度控制所带来的速度扰动叠加的速度变化，对轧件在冷却区的运动进行精确的位置跟踪，并在冷却区中增设速度补偿区，对设定的冷却规程进行更新以补偿升速带来的冷却不足或降速引起的过冷。新的卷取温度模型以辊间冷却为计算单元，可有效地集成不同的冷却形式，并对变速轧制过程进行有效适应。自现场应用以来，卷取温度设定精度和控制稳定性大幅度提高。
침대인변속알제화복합냉각대래적권취온도모형예보정도강저적문제，이열수출곤도상적냉각설비포치신식화곤간냉각환열형식위출발점，채용Crank-Nicolson( C-N)륙점격식유한차분방법구건알건알후냉각온도계산모형；이전궤위주、반궤위보，불단진행자학습래대알건냉각온도진행공제，재정알출구안조고정시간주기대알건진행분단채양화전궤설정，재권취입구안조장도진행분단채양화주기성반궤공제；위사모형괄응승속알제화인종알온도공제소대래적속도우동첩가적속도변화，대알건재냉각구적운동진행정학적위치근종，병재냉각구중증설속도보상구，대설정적냉각규정진행경신이보상승속대래적냉각불족혹강속인기적과랭。신적권취온도모형이곤간냉각위계산단원，가유효지집성불동적냉각형식，병대변속알제과정진행유효괄응。자현장응용이래，권취온도설정정도화공제은정성대폭도제고。
To solve the problem that coiling temperature deviation is enlarged under speed up rolling condition or under complex cooling devices, a runout table cooling model was developed based on Crank-Nicolson finite difference method . The layout information such as table roll position, spraying header position, nozzle size and cooling type between table rolls were used in temperature calculation for hot-rolled strip cooling after rolling. Feedforward and feedback loops were implemented in the coiling temperature control ( CTC ) model. Based on scanned data, CTC performed product-to-product adaptations of model parameters to follow changing process conditions. The rolled strip left from finishing mill was virtually divided by a constant time interval into segments with different length. Cooling schedule for each segment was made by CTC model according to the measured finishing temperature, rolling speed and actual thickness. The segment position was precisely tracked when it moved on runout table. A new cooling sub-zone was designated to open or close the valves to compensate the insufficient cooling or to reduce the overcooling for segment located in cooling zone because of the speed variable brought by speed-up rolling and additional speed incremental given by finishing temperature control ( FTC ) . Since the on-site application of the new CTC model, coiling temperature control along the whole strip length has been obviously improved in coiling temperature homogeneity and stability.