Water injection controller, water injection control method, and water injection control program for rolling lines

1. A water injection controller for rolling lines adapted to use cooling water stored in a tank to cool a rolling material in a rolling line and collect used cooling water to return to the tank by a pump system, the water injection controller for rolling lines comprising:

a cooling water usage predictor configured to take information pertinent to cooling the rolling material as a basis to predict, for a respective prescribed prediction cycle T 1 , a usage of cooling water in a prescribed prediction target period T 2 ;

a constrained running condition predictor configured to take the usage of cooling water predicted by the cooling water usage predictor as a basis to predict, for the respective prescribed prediction cycle T 1 , a running condition of the pump system in the prediction target period T 2 meeting a prescribed constraint condition;

an energy consumption calculator configured to take the running condition of the pump system as a basis to calculate a quantity of energy to be consumed for an operation of the pump system in the prediction target period T 2 ;

an optimizer configured to operate, for the respective prescribed prediction cycle T 1 , to change the running condition of the pump system predicted by the constrained running condition predictor, to give to the energy consumption calculator, to have the energy consumption calculator calculate a plurality of quantities of energy to be consumed, and determine an optimal quantity of energy to be consumed among the plurality of quantities of energy to be consumed that the energy consumption calculator has calculated; and

a pump system running controller configured to control a running of the pump system having as a target value therefor a running condition of the pump system making the optimal quantity of energy to be consumed that the optimizer has determined.

2. The water injection controller for rolling lines according to claim 1 , wherein the constrained running condition predictor comprises:

a running condition predictor configured to take the usage of cooling water predicted by the cooling water usage predictor as a basis to predict, for the respective prescribed prediction cycle T 1 , a running condition of the pump system in the prediction target period T 2 ; and

a running condition corrector configured to determine whether or not the prescribed constraint condition is met by the running condition of the pump system predicted by the running condition predictor, and operate simply when the constraint condition is unmet by the running condition of the pump system, to correct the running condition of the pump system to meet the constraint condition.

3. The water injection controller for rolling lines according to claim 1 , further comprising:

a constraint condition monitor configured to monitor in real time a quantity of state of the rolling line pertinent to the prescribed constraint condition, and monitor whether or not the prescribed constraint condition is unmet by the quantity of state of the rolling line; and

a target value corrector configured to operate when the constraint condition monitor has determined the prescribed constraint condition as being unmet by the quantity of state of the rolling line, to correct the target value of the pump system running controller to have a quantity of state of the rolling line residing within the prescribed constraint condition.

4. The water injection controller for rolling lines according to claim 1 , wherein

the cooling water usage predictor comprises

a direct usage predictor configured to input operational information on a used water quantity and time-dependent variations of cooling water for a current cooling rolling material as information pertinent to cooling the rolling material, and take the operational information as a basis to predict, for a respective prescribed prediction cycle T 1 , a usage of cooling water in a prescribed prediction target period T 2 .

5. The water injection controller for rolling lines according to claim 1 , wherein

the cooling water usage predictor comprises

an indirect usage predictor configured to store therein a reference table including information on attributes of past cooled rolling materials associated with usages for the past cooled rolling materials, input attribute information of a current cooling rolling material as information pertinent to cooling the rolling material, and take the attribute information as a basis to refer to the reference table and predict, for a respective prescribed prediction cycle T 1 , a usage of cooling water in a prescribed prediction target period T 2 .

6. The water injection controller for rolling lines according to claim 5 , wherein

the cooling water usage predictor further comprises

a usage learner configured to input a usage of cooling water for a past cooled rolling material to perform a prescribed learning thereon, and use the usage after the learning to update a usage for the past cooled rolling material in the reference table stored in the indirect usage predictor, and

the indirect usage predictor is configured to

input attribute information of the current cooling rolling material as information pertinent to cooling the rolling material, and take the attribute information as a basis to refer to the reference table and predict, for a respective prescribed prediction cycle T 1 , a usage of cooling water in a prescribed prediction target period T 2 .

7. The water injection controller for rolling lines according to claim 1 , wherein

the cooling water usage predictor comprises:

a direct usage predictor configured to input operational information on a used water quantity and time-dependent variations of cooling water for a current cooling rolling material as information pertinent to cooling the rolling material, and take the operational information as a basis to predict, for a respective prescribed prediction cycle T 1 , a usage of cooling water in a prescribed prediction target period T 2 ;

an indirect usage predictor configured to store therein a reference table including information on attributes of past cooled rolling materials associated with usages for the past cooled rolling materials, input attribute information of a current cooling rolling material as information pertinent to cooling the rolling material, and take the attribute information as a basis to refer to the reference table and predict, for a respective prescribed prediction cycle T 1 , a usage of cooling water in a prescribed prediction target period T 2 ; and

a usage learner configured to input a usage of cooling water for a past cooled rolling material to perform a prescribed learning thereon, and use the usage after the learning to update a usage for the past cooled rolling material in the reference table stored in the indirect usage predictor, and

is configured to have the direct usage predictor or the indirect usage predictor predict a usage of cooling water in an adaptive manner depending on input information pertinent to cooling the rolling material.

8. The water injection controller for rolling lines according to claim 1 , wherein

the prescribed prediction cycle T 1 and the prescribed prediction target period T 2 have a relation in between such that T 1 ≦T 2 .

9. The water injection controller for rolling lines according to claim 1 , wherein

the prescribed constraint condition comprises one or more of upper and lower limit values of a water level or a retained water quantity in the tank, a minimal value in number of running ones of pumps constituting the pump system, and a minimal value of an output of electric motors running to drive pumps.

10. A water injection control method for rolling lines adapted to use cooling water stored in a tank to cool a rolling material in a rolling line and collect used cooling water to return to the tank by a pump system, the water injection control method for rolling lines comprising:

a step of taking information pertinent to cooling the rolling material as a basis to predict, for a respective prescribed prediction cycle T 1 , a usage of cooling water in a prescribed prediction target period T 2 ;

a step of taking the predicted usage of cooling water as a basis to predict, for the respective prescribed prediction cycle T 1 , a running condition of the pump system in the prediction target period T 2 meeting a prescribed constraint condition;

a step of taking the predicted running condition of the pump system as a basis to calculate a quantity of energy to be consumed for an operation of the pump system in the prediction target period T 2 ;

a step of operating, for the respective prescribed prediction cycle T 1 , to change the predicted running condition of the pump system, to calculate a plurality of quantities of energy to be consumed, and determining an optimal quantity of energy to be consumed among the plurality of calculated quantities of energy to be consumed; and

a step of having a running condition of the pump system making the optimal quantity of energy to be consumed as a target value to drive the pump.