Page 379 - Design of Simple and Robust Process Plants

366 Chapter 9 Operation Optimization
Fundamental-based models are mostly a mixture of detailed described process sec-
tions, short-cut described part based on fundamentals, and empirical models. How-
ever, it should be noted that the more fundamental the bases for the models, the
higher the value of the models for understanding and upgrading the process.
The fundamental as well as the empirical approaches for optimization are both
embedded in a framework for execution of the optimization cycle.

9.5.2
The Optimization Cycle

The optimization cycle, which is operated by an executive to manage the implemen-
tation of CLO, is composed out of the following sequential steps, called modules
(see Figure 9.2):
. Data analysis
. Data reconciliation
. Simultaneous data reconciliation and parameter estimation
. Optimization
. Implementation

Process

Control Data
Data analysis Decider-1
system input Data analysis
Steady state
Reduced Data
Decider-2
model reconcil.
Mass & Component balances
Rigorous Parameter
Decider-3
model Estimation
Up dated model Parameters
Up dated
Optimization Decider-4
Rig. model
Set point
implementation
Up dated set points

Fig. 9.8. System architecture for closed loop optimization,
J. Krist et al., 1994.