| 摘要 |
PURPOSE:To improve the quality of cast products by controlling the flow rate of spraying water in the secondary cooling zone for continuous casting by detecting the temp. distributions in the section of an ingot and the thickness of its solidified shell with high accuracy. CONSTITUTION:Upon starting of drawing of an ingot from a mold 2, with the meniscus 4 thereof as a starting surface, a tracking surface (chain line) is assumed at every constant length LS and the temp. distribution in the section of the ingot 3 is calculated at every constant time. The one-dimensional nonsteady heat conduction model dividing the section to the shape of a square shell is used for this calculation. On the other hand, said model is corrected by the coeffts. of heat transfer learned from the relations between the calculated temps. on the outlet side of the respective zones (a), (b)- and the temps. measured actually with thermometers (ta), (tb)-. The temp. distribution of each tracking surface in each temp. measurement point is forecast at every constant time in accordance with the corrected model. The feed forward water flow rate determined from the difference between the forecast temp. in said position and the target temp. and the feedback water flow rate determined from the difference between the actually measured temp. and the target temp. are added and the water is sprayed to the ingot at this added water flow rate. |
