热轧辊瞬态温度场快速仿真模型

Research on the quick simulation model for the transient temperature field of the hot roll

利用等效温度法和变步长差分法建立了轧辊瞬态温度场快速仿真模型。综合考虑水冷、空冷、轧辊与轧件接触热传导等动边界条件,利用等效温度模拟轧辊表面的瞬态温度变化;对轧辊内部单元划分不等距网格,沿轧辊高向(从表层到中心)以及沿轧辊横向(从中部到两端),逐渐增加单元步长,提高模型的计算精度和计算速度;基于台劳展开式推导瞬态热传导方程的变步长差分式,模拟非稳态轧制及停轧空冷时的轧辊瞬态温度变化情况。工业实际数据验证了仿真模型的正确性和可行性,实验结果与仿真结果吻合较好,适合工程在线快速计算,预报精度在±5℃以内。

Used the equivalent thermal method and the variable-step difference method, the fast simulation model of roll transient temperature field was established. Some important dynamic boundary conditions, such as water cooling, air cooling, contact heat conduction between the roll and the plate and so on, were comprehensively considered, transient temperature change on the roll surface could be simulated by the equivalent temperature. Unequal distance grids were divided in the roll interior, for instance, along the height direction （from surface to center） and the lateral （from middle to both sides） of roll, the step-length was increased gradually, to improve calculation precision and computing speed of the model. Based on the Taylor-Expansion-Inferential, reasoning the variable-step difference type of the transient heat conductivity equation, then change of the roll transient temperature at the unsteady state rolling and the air cooling state after rolled were simulated. The industry actual datum have confirmed accuracy and feasibility of the simulation model, the experimental result and the simulation result tallies well, the computation speed and the precision have distinct enhancement, suited to the online rapid calculation. The forecast precision of roll temperature can be accurately controled within ±5℃.