Control device for cooling apparatus

A control device for a cooling apparatus that is provided at a rolling line and is configured to cool a material to be rolled by a plurality of cooling banks,

• wherein the control device is configured to control each of water injection amounts in the plurality of cooling banks such that a delivery side temperature target value indicating a target temperature of the material to be rolled at a position of a delivery side pyrometer provided at a delivery side of the cooling apparatus corresponds to a delivery side temperature actual value indicating an actual temperature of the material to be rolled that is measured by the delivery side pyrometer,
• wherein, in the control of each of the water injection amounts in the plurality of cooling banks, the control device is configured to perform preset calculation, cooling history management, feedforward calculation, and feedback calculation,
• wherein, in the preset calculation, the control device is configured to:
• set each of the plurality of cooling banks to be a feedforward bank for performing feedforward control of the water injection amount, or a feedback bank for performing feedback control of the water injection amount, the feedback bank being at least one cooling bank that is allocated in order from a downstream side in the rolling line according to the material to be rolled, the feedforward bank being a remaining cooling bank;
• calculate a delivery side temperature prediction value indicating a predicted temperature of the material to be rolled at the position of the delivery side pyrometer;
• and
• calculate each of the water injection amounts in the plurality of cooling banks such that the delivery side temperature prediction value corresponds to the delivery side temperature target value,
• wherein, in the cooling history management, the control device is configured to:
• grasp a position of the material to be rolled for each of segments indicating one section at a time of dividing the material to be rolled into a virtual length in a conveyance direction;
• and
• store a cooling history including an actual speed of the material to be rolled at each of positions of the plurality of cooling banks, and a history of each of the water injection amounts in the plurality of cooling banks, for each of the segments,
• wherein, in the feedforward calculation, the control device is configured to:
• calculate the delivery side temperature prediction value for each of the segments, based on an entry side temperature actual value indicating an actual temperature of the material to be rolled at a position of an entry side pyrometer provided at an entry side of the cooling apparatus, and a speed of the material to be rolled at the position of the entry side pyrometer;
• and
• change each of the water injection amounts in the feedforward banks that are calculated in the preset calculation, based on a difference between the delivery side temperature target value, and the delivery side temperature prediction value calculated for each of the segments,
• wherein, in the feedback calculation, the control device is configured to calculate a difference between the delivery side temperature actual value and the delivery side temperature target value for each of the segments,
• wherein, in the cooling history management, the control device is further configured to set a recalculation position for re-executing the feedback calculation, the re-calculation position being located at an upstream side in the rolling line from a position of the feedback bank by a distance corresponding to a response delay of the feedback bank,
• wherein, when a segment reaches the recalculation position, the control device is further configured to perform recalculation of the delivery side temperature prediction value for the segment that reaches the recalculation position, based on the cooling history, and
• wherein, in the feedback calculation, the control device is further configured to:
• when the segment reaches the recalculation position, calculate a temperature correction value for compensating a delay due to a conveyance time period from the position of the feedback bank to the position of the delivery side pyrometer, and a response delay of the feedback bank;
• and
• change each water injection amount in the feedback bank calculated in the preset calculation for each of the segments, based on the delivery side temperature target value, the delivery side temperature actual value calculated for each of the segments, the recalculated delivery side temperature prediction value, and the temperature correction value.