Page 397 - Design of Simple and Robust Process Plants

384 Chapter 9 Operation Optimization
For the technical details, reference is made to the feasibility study, although many
technical details will need to be obtained during the modeling and the control
design.

9.6.3
Develop and Install Performance Measurement and Start Tracking Process
Performance: Step 2

The performance measurement is one of the first attributes to be installed in the
process plant. The design of the performance meter is described in Section 9.4. One
of the most important functions is to track the performance of the process before
optimization is installed. This will be the baseline for the evaluation of the project.
During these observations, we most likely measure the performance of the process
at fixed price sets. The accuracy of the process model to be achieved is not yet
known, but the savings are already estimated and these should be measured at least
at an accuracy of 10%. This sets the accuracy of the performance meter.

9.6.4
Develop Control Structure with CVs, MVs, and DOFs: Step 3

The overall control structure with a split between basic control (BC), MBC and opti-
mizer manipulating set-points is determining the control activities. Examples of
control configuration for a simple distillation and a reactor system are given in Fig-
ures 9.12 and 9.13 and are represented in Tables 9.3 and 9.4.

MBC
P
COOLING WATER
s.p
Q MBC
MBC or O.O
L
F
F
O.O MBC PRODUCT A
Q F
FEED

STEAM
L

PRODUCT B

Fig. 9.12. Control hierarchy round a distillation column.