Large-Scale Controller Performance, Assessment, Diagnosis and Improvement Mike Paulonis Eastman...
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Transcript of Large-Scale Controller Performance, Assessment, Diagnosis and Improvement Mike Paulonis Eastman...
Large-Scale Controller Performance,Assessment, Diagnosis and Improvement
Mike PaulonisEastman Chemical Company
Presentation to: East TN AIChEFeb 2005
MAP 2005 2
Collaboration
Co-creator of controller performance assessment at Eastman
John Cox
MAP 2005 3
Agenda
Productivity – The Driver Circumstances Leading to Development System Overview Performance Assessment Details / Screenshots Application Results Summary
MAP 2005 4
Eastman productivity
Volume sold Employees
15 years ago
1 X 19,000
Today 2 X 12,000
Tremendous productivity gains (~ 8%/yr) !
MAP 2005 5
Sources of productivity
ProcessAutomation
InformationTechnology
ProcessImprovement
Morevolume
Fewerpeople
MAP 2005 6
A closer look at process automation
Generating productivity Enable stable plant operation at higher rates Enable a higher percentage of first-class product Enable plants to run safely with fewer operators
Affected by productivity changes
Year AdvCT employees
1993 17
1999 14
2005 11
MAP 2005 7
Increase in process control work on existing plants revealed many control loops with poor performance
Partial cause was a decrease in number and availability of personnel to monitor/troubleshoot control loops
Control loop/valve maintenance mode was “run until failure”
The need for a system to efficiently detect and diagnose poor control loops became apparent
Increase control engineer productivity Enable plant engineers to do more on their own
Focus on 1999
MAP 2005 8
More from 1999…
Honeywell introduced "Loop Scout" to general customers
The good: assess control loop performance from historical operating data
The bad: Cost: $350 per loop per analysis! Only accepted data from Honeywell control systems Have to send the controller data to Honeywell for
analysis
MAP 2005 9
We can do better (we think)
Our vision for controller performance assessment
Interfaces to all Eastman control and data systems Analyze thousands of loops automatically and
periodically Rank loop performance to quickly find opportunities Users can pull up current or historical performance of
any loop (interactive discovery) Users can get email reports on controller performance
specific to their plant (exception processing) Reports have summaries understandable by anyone
and details for in-depth analysis by control engineers Capture controller tuning changes which often link
with performance issues
MAP 2005 10
Read a lot of academic papers Implemented assessment algorithms in Matlab Tested/improved using real plant data Automated the capture of bulk data from control
systems Automated the analysis of bulk data Improved some more – hand tuned classification
algorithm from about 100 example loops Built a database to house all the analysis results
and service user queries Built a web application using Cold Fusion to bring
it all together and make it accessible to everyone
Build it!
MAP 2005 11
System architecture
Distributed data collection Distributed computing resources Server-side web programming Linked in to wide-area network
DCS 1App Host 1
w/Data Interface
User B
User A
File Server
Computation
Engine
Web Server
System
DCS 2App Host 2
w/Data Interface
Database
LAN
MAP 2005 12
Eastman’s large-scale system
Ten sites Forty-nine process areas Interfaces to a variety of
control systems
Daily tuning history on 14,000 loops
Weekly performance history on 8,500 loops
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Use mode 1 - Tell me about a loop
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MAP 2005 15
Example help
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Use mode 2 - Find problem loops
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Find problem loops
Worst
Best
MAP 2005 18
Push content for busy people
Email subscription reports Monthly performance detail
Top 20 losers and gainers Rankings worst to best
Monthly performance summary Performance by loop type Performance by loop type over the last year Performance benchmark Eastman-wide
Daily tuning changes Notification - tuning changes often mean other
problems Monthly tuning detail
MAP 2005 19
Email examples
MAP 2005 20
Neat pictures, but does it really work?
Primary question around valve problems
Controller performance assessment showed many problems
Most seemed to be valve-related, not tuning
Valves need maintenance - culture change
Valve repair/replacement costs $$$
Don't want a lot of false positives on valve diagnoses
Open it 100%, OK, now close
it!
MAP 2005 21
Valve travel testing
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
50000
100000
150000
200000
250000
5 10 15 20 25
ValStat Valve Performance
Dis
tanc
e F
rom
Sea
t, [
inch
]
Fric
tion,
[ lb
f ]
Control Signal, [ ma ]
Increasing Signal Decreasing Signal *Friction
PROTUNER™
ValStat
MAP 2005 22
Polymer controller improvement project
Control Loop Diagnosis Repair
HR2 Spray Recirc Temp Hdw/sticking Add positioner
GR2 Spray Recirc Temp Hdw/sticking Add positioner
FR2 Spray Recirc Temp Hdw/sticking Add positioner
H MeOH Column Reflux Hdw/sticking Fix valve diaphragm
H MeOH Column Level Hdw/hysteresis Replace valve
J MeOH Column Level Hdw/unspecified Replace valve
F MeOH Column Level Hdw/sticking Engage positioner
DR2 Level Hdw/unspecified Repair positioner
C Paste EG Temp Hdw/sticking Repair positioner
HR1A Preht Dow Temp Hdw/sticking Replace valve
MAP 2005 23
Example performance improvement
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Second pass - entire classes
Reactor Dowtherm control valves all have motion problems (some up to 15% deadband)
Why? Long stem High-temp packing Dirty conditions No positioner
Solution? Critical service Replace all
A significant milestone!
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The trend looks good
New Dowtherm Valves
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Improvement in every category
December 2000 September 2002
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Beating the “competition”
December 2000
12th of 24 areas
50th percentile
September 2002
30th of 36 areas
83rd percentile
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The payoff (2001 vs. 2000)
Reduction in off-class production Reactor level - 272 klbs (80% reduction) Reactor temperature - 52 klbs (80% reduction) Vacuum - 119 klbs (35% reduction) Product specs - 96 klbs (35% reduction) 98.5% class 1 production - best ever
Reduction in startup and transition off-class 8.1 klb/startup (22%), 19.3 klb/transition (70%) Over 1 million lb/year - maybe 15-25% from control
Line run-life H-line best ever 222 days (9/10/01 - 4/19/02)
Customer complaints down 55%
MAP 2005 29
Controller Performance by Type(unfiltered)
40
45
50
55
60
65
70
75
80
Apr-0
0
Jul-0
0
Oct-
00
Jan-
01
Apr-0
1
Jul-0
1
Oct-
01
Jan-
02
Apr-0
2
Jul-0
2
Oct-
02
Jan-
03
Apr-0
3
Jul-0
3
Oct-
03
Jan-
04
Apr-0
4
Jul-0
4
Oct-
04
Co
mp
os
ite
Sc
ore Flow
Pressure
Level
Temperature
Long-term monitoring
Improve Maintain the gain Improve
MAP 2005 30
The bottom line
A revolution in knowledge for users of all levels Find problems that are not obvious Troubleshooting time reduced by 2/3 or more Monitor and benchmark performance over time
for continual improvement Enables effective approach to controller
maintenance Encourages communication between control
engineers, staff engineers, area managers, and maintenance forces
Generates significant economic gains
MAP 2005 31
Another example
Another polymers area embarked on a control improvement project in 2003 using performance assessment to identify opportunities and track results
Focused on problem loops critical to operation Added smart positioners to key valves Replaced some undersized valves Fixed some slave controller wind-up problems Implemented measurement filters where appropriate Did some control strategy redesign Much more…
MAP 2005 32
Great results!
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In search of excellence
MAP 2005 34
Other areas can do this too
Engineer signs up for monthly reports Engineer receives and reviews monthly reports
What is bad, what is good? Get management buy-in
Control loops need maintenance Controller performance is important
Engineer prioritizes loops Criticality, return on investment
Enlist help of CSM, E&I shops, Reliability Technology and AdvCT as needed
Engineer arranges funding and schedule for fix Engineer follows up to identify tangible
benefits
MAP 2005 35
Summary
Controller performance can be determined from historical operating data
Eastman's home-grown system does this weekly for thousands of controllers world-wide
Users can get performance information from a web site and/or have it emailed to them
With the system, work can quickly be focused on the best opportunities
Improved controller performance leads to improved process performance and greater profitability
We can now do much more with less