MATERIAL AND ENERGY BALANCE RECONCILIATION PROCESS CONTROL METHOD AND APPARATUS

摘要

ABSTRACT OF THE DISCLOSUREA method for controlling a system parameter basedon controlling a setpoint for a process control variableincludes measuring the rate of input to and output from avessel. The difference between the input and output ratesis determined to provide an expected rate of accumulationin the vessel. The actual rate of accumulation in thevessel is measured. The difference between the expectedrate of accumulation and the actual rate of accumulation isdetermined to provide a bias term. A value for the setpointfor the process control variable is calculated by solvingone of a material or energy balance equation which includesthe bias term and a term representative of a predeterminedtime period during which the controlled parameter is toreach a desired value. The setpoint for the process controlvariable is then controlled based on the calculatedsetpoint value. An apparatus is disclosed for carrying outthe disclosed method.