Abstract: A temperature calculation method includes: dividing a cross section perpendicular to a longitudinal direction of a steel plate to be hot-rolled into a plurality of rectangular elements; and calculating a temperature of each of the rectangular elements using a finite difference method. A first region 31 that includes an edge part of the cross section is divided such that a plurality of the rectangular elements are lined up in a plate-thickness direction and such that a plurality of the rectangular elements are lined up in a plate-width direction. A second region 32 that includes a center of the cross section and is wider than the first region 31 is divided such that a plurality of the rectangular elements are lined up in the plate-thickness direction but the second region 32 is not divided in the plate-width direction.

Abstract: A temperature calculation method includes: dividing a cross section perpendicular to a longitudinal direction of a steel plate to be hot-rolled into a plurality of rectangular elements; and calculating a temperature of each of the rectangular elements using a finite difference method. A first region 31 that includes an edge part of the cross section is divided such that a plurality of the rectangular elements are lined up in a plate-thickness direction and such that a plurality of the rectangular elements are lined up in a plate-width direction. A second region 32 that includes a center of the cross section and is wider than the first region 31 is divided such that a plurality of the rectangular elements are lined up in the plate-thickness direction but the second region 32 is not divided in the plate-width direction.

Abstract: A water injection controller and method usable in rolling lines using stored cooling water to cool a material. A cooling water usage predictor predicts, for a respective prescribed prediction cycle, usage of cooling water in a prescribed prediction target period. A constrained running condition predictor takes the predicted cooling water usage to predict a required running condition of a pump system in the prediction target period meeting a prescribed constraint condition. An energy consumption calculator takes the predicted running condition of the pump system to calculate an energy quantity to be consumed. An optimizer determines an optimal energy quantity to be consumed among plural energy quantities to be consumed under changed running conditions of the pump system. A pump system running controller controls running of the pump system having as a target value therefor a running condition of the pump system requiring the optimal quantity of energy to be consumed.

Abstract: A cooling water usage predictor predicts, for a respective prescribed prediction cycle T1, a usage of cooling water in a prescribed prediction target period T2, a constrained running condition predictor takes the predicted usage of cooling water as a basis to predict a required running condition of a pump system in the prediction target period T2 meeting a prescribed constraint condition, an energy consumption calculator takes the predicted running condition of the pump system as a basis to calculate a quantity of energy to be consumed, an optimizer determines an optimal quantity of energy to be consumed among a plurality of quantities of energy to be consumed under changed running conditions of the pump system, and a pump system running controller controls a running of the pump system having as a target value therefore a running condition of the pump system requiring the optimal quantity of energy to be consumed.