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Instrumentation Upgrade
The problem of instrumentation network design and
upgrade consists on determining the optimal set of
measured variables and selecting the accuracy and reliability of
the corresponding instruments. The goal is to obtain sufficiently
accurate and reliable estimates of variables of interest while at
the same time, be able to filter bad data due to possible
instrument malfunction.
Instrumentation Upgrade Goals:
Given a set of key
variables, several goals exist for every designer of a set of
instruments in a plant.
- Cost: investment and maintenance. This is the primary target
for our studies.
- Estimability: Ability to estimate a variable using hardware
or software.
- Precision: Accounting usually sets the level, but on line
optimization needs may supersede these.
- Reliability
- Gross Error Robustness: Bias and leak detectability, residual precision left after failures, effect of undetected bias.
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VALUE: A
Recently developed theory enables us to assess this value.
Typical Upgrade Project
1) Evaluation
: Given a P&ID of the process
and a simulation we determine:
- Observability and Precision of estimates upon data
reconciliation
- Ability to detect bias and leak, gross error robustness.
Impact on loss revenue.
- Modifications to maintenance policies.
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VALUE
OF EXISTING INSTRUMENTATION AND POTENTIAL
2) Upgrade Study
:
After setting upgrade goals with the client,
we provide a list of new instruments and relocation of existing
instruments that is needed to achieve the desired performance
at a minimum cost or maximum expected worth. We
also assess the financial risk associated.
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