STATE PREDICTION METHOD FOR PROCESS AND PROCESS CONTROL UNIT USING THE SAME

PROBLEM TO BE SOLVED: To provide a state prediction method for process that shortens a calculation time by composing a multiple regression model which consists of less explanation variables than before and has high precision, and a process control unit using the same.SOLUTION: A process control unit 10 includes a process prediction part 31 which predicts chimney exit NOx concentration based upon the multiple regression model constructed by the state prediction method for process, and a predictive control part 32 which determines an ammonia suction blowing-in amount based upon a predicted value of chimney exit Nox concentration calculated by the process prediction part 31. Further, the state prediction method for process includes: selecting explanation variables constructing the multiple regression model from a time-series database in which time history data on process variables indicative of an operation state of process are accumulated; narrowing down explanation variables in a stepwise method and then checking whether partial regression coefficients of the narrowed-down explanation variables are plus or minus; and excluding explanation variables indicative of an action reverse to an actual phenomenon.