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Lecture Chemical process control - Chapter 19

a | Chapter 19 Real-Time Optimization RTO In previous chapters we have emphasized control system performance for load and set-point changes. Now we will be concerned with how the set points are specified. In real-time optimization a computer is used to optimize set points for control loops. Implementation of RTO Supervisory Control 1 Set point calculations are performed on a digital computer e.g. steady-state optimization . 2 Set points could be transmitted to either a analog controllers before 1990 b digital controllers after 1990 3 Case a is referred to as analog supervisory control case b is direct digital control . Chapter 19 days-months 5. Planning and scheduling f hours-days 4. Real-Time optimization y minutes-hours 3b. Multivariable and constraint control seconds-minutes 3a. Regulatory control 5 1 second 2. Safety environmental equipment protection y f 1 second 1. Measurement and actuation y z X Process J Demand forecasting supply chain management raw materials and product planning scheduling Plant-wide and individual unit real-time optimization parameter estimation supervisory control data reconciliation Multivariable control model predictive control PID control advanced control techniques control loop performance monitoring Alarm management emergency shutdown Sensor and actuator validation limit checking Figure Í9.1 The five levels of process control and optimization in manufacturing. Time scales are shown for each level. Chapter 19 Figure 19.2 A block diagram for RTO and regulatory feedback .