Transcript Automated Recovery Boiler Sootblowing Control System Barbara G. Haley; B.A., Accounting; C.P.A. University of South Alabama; Mobile, AL Floyd I.

Automated Recovery Boiler Sootblowing
Control System
Barbara G. Haley; B.A., Accounting; C.P.A.
University of South Alabama; Mobile, AL
Floyd I. Lawrence; B.S., Electrical Engineering
University of Iowa; Iowa City, IA
Brad S. Carlberg, P.E.; B.S., Mechanical Engineering
Washington State University; Pullman, WA
Ford, Bacon & Davis, LLC
Mobile, AL
James A. Johnson; B.S. Electrical Engineering
Louisiana Tech; Ruston, LA
Ford, Bacon & Davis, LLC
Monroe, LA
2001 TAPPI PCE&I / ISA PUPID Joint Conference
March 27, 2001
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Automated Recovery Boiler Sootblowing Control System

The mill’s OTHER Recovery Boiler sootblowers were
already controlled by a pair of redundant PLC’s

The existing sootblower panel was beginning to take
more maintenance time - “it was wearing out”

Operators wanted “better” control:
sootblower sequences, etc.

E&I technicians wanted “better” diagnostics to help
find failed field devices

Superintendent wanted better tracking of failed field
devices to determine cause of shutdowns
2001 TAPPI PCE&I / ISA PUPID Joint Conference
March 27, 2001
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Automated Recovery Boiler Sootblowing Control System

Team Effort Assured Smooth Start-Up
PLC Code Programming
 Backup HMI Programming
 DCS Programming
 Installing New I/O Cables
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
Dynamic Simulation in PLC tested PLC code Prior to
Start-up / Commissioning

Cutover Completed in Two-Week Yearly Shutdown

Recovery Boiler & Sootblowers Started Up On Time

50% of team on-site at startup
2001 TAPPI PCE&I / ISA PUPID Joint Conference
March 27, 2001
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Automated Recovery Boiler Sootblowing Control System
UNEFFECTED
Field Device’s
NEW
REDUNDANT PLC’s
UNEFFECTED
UNEFFECTED
Intermediate
Junction Box
in MCC
New I/O Cables
from MCC
Existing I/O Cables
from MCC
“Blue Hose”
REMOVED
Sootblower Control Panel
2001 TAPPI PCE&I / ISA PUPID Joint Conference
Back-Up HMI
NEW
Existing DCS
Added NEW Screens
March 27, 2001
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Automated Recovery Boiler Sootblowing Control System

The Automated Recovery Boiler Sootblower System Operates
basically the same as the original panel-mounted controller;
EXCEPT for greater visibility

The Automated Recovery Boiler Sootblower System Operates the
Same on Both the DCS Operator Interface and the Redundant,
Backup, Plasma Screen Operator Interface

The Operator Interface and the DCS Are Talking to the Same PLC
and Reading the Same Points

The PLC Does Not Care Which System Sends It Information, It
Will Simply Process the Information As It Is Received
2001 TAPPI PCE&I / ISA PUPID Joint Conference
March 27, 2001
Page 5
Automated Recovery Boiler Sootblowing Control System
 Six
(6) Display Screens:
 Sootblowing
Control
 Manual Mode Blower Select
 Automatic Sequence Blower Out of Service
 Limit Switch Monitoring
 Help Screens
 Alarm screens
2001 TAPPI PCE&I / ISA PUPID Joint Conference
March 27, 2001
Page 6
Automated Recovery Boiler Sootblowing Control System
Main Display Screen
2001 TAPPI PCE&I / ISA PUPID Joint Conference
March 27, 2001
Page 7
Automated Recovery Boiler Sootblowing Control System
3 PRE-DETERMINED SOOTBLOWING SEQUENCES
 ALL Sootblowers in ASCENDING Order
 Economizer Sequence (1-32, then 1-52)
 Generator Plugging Sequence (5-8,15-18,25-28,1-52)
FOUR (4) OPERATING MODES
Steam Mode Automatic Control Mode
Steam Mode Continuous Control Mode
Sequence Continuous Cycle Mode
Sequence Single Cycle Mode
2001 TAPPI PCE&I / ISA PUPID Joint Conference
March 27, 2001
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Automated Recovery Boiler Sootblowing Control System
Manual Mode Blower Select
2001 TAPPI PCE&I / ISA PUPID Joint Conference
March 27, 2001
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Automated Recovery Boiler Sootblowing Control System
Automatic Sequence Sootblower Out of Service
2001 TAPPI PCE&I / ISA PUPID Joint Conference
March 27, 2001
Page 10
Automated Recovery Boiler Sootblowing Control System
Limit Switch Monitoring
2001 TAPPI PCE&I / ISA PUPID Joint Conference
March 27, 2001
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Automated Recovery Boiler Sootblowing Control System
Alarm Notification Screen
2001 TAPPI PCE&I / ISA PUPID Joint Conference
March 27, 2001
Page 12
Automated Recovery Boiler Sootblowing Control System
Help Screens
2001 TAPPI PCE&I / ISA PUPID Joint Conference
March 27, 2001
Page 13
Automated Recovery Boiler Sootblowing Control System
I/O Count
56 Digital Input - 4 ea 16 point cards
(4 for Even/Odd Fwd/Rev & 52 for each Soot Blower)
156 Digital Output - 11 ea 16 point cards
(3 limit switches for each of 52 Soot Blowers)
I/O Racks
2 16-slot racks - with single slot addressing
with scanner cards in each rack
Communication
Only 2 channels used (1A-DH+ & 1B-RIO)
Communicates to DCS via Extended PLC Gateway
2001 TAPPI PCE&I / ISA PUPID Joint Conference
March 27, 2001
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Automated Recovery Boiler Sootblowing Control System
CONCLUSIONS
 Pre-Existing, Hard-Wired Field Devices UNAFFECTED
 Pre-Existing, Stand-Alone Sootblower Panel REMOVED
 Redundant PLC’s Assure Constant Control





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DCS and Backup HMI Assure Constant Visibility
DCS Continuously Collects the Plant’s Real-time Process Data
Operators Have Greater Access to That Real-time Process Data
3 Strategic, Pre-Determined Sootblowing Sequences
 ALL Sootblowers in ASCENDING Order
 Economizer Sequence (1-32, then 1-52)
 Generator Plugging Sequence (5-8,15-18,25-28,1-52)
 Easy to implement 15 more sequences by “fill-in-the-blanks”
E&I Technicians Can Quickly Find and Troubleshoot Failed Field
Devices From the Alarm Display
Better Control of Sootblowers
Optimally Operate the Recovery Boiler.
2001 TAPPI PCE&I / ISA PUPID Joint Conference
March 27, 2001
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Automated Recovery Boiler Sootblowing Control System
MORE CONCLUSIONS

The Plant Saved Resources (i.e.; Steam) and Reduced Plant
Operating Costs Significantly by “Smoothing” Steam Demand

The Plant Only Blows Soot When It Is Needed, and Only in the
Necessary Locations (i.e.: Economizer or Generator Tube Banks)
Automated Sootblowing Improves Boiler Heat Rate, Minimizes
Soot Accumulation, Improves Overall Boiler Efficiency, and
Balances Blowing Sequences
The Plant Is Able to Avoid Unnecessary Steam Usage and Opacity
Spikes
Plant Equipment Life Was Extended and the Plant Now Avoids
Forced Outages Due to Soot Accumulation




The Operators Can Use the Additional Real-time Process Data and
Alarm Management Display to Schedule Sootblowing Sequences
and Optimally Operate the Recovery Boiler
2001 TAPPI PCE&I / ISA PUPID Joint Conference
March 27, 2001
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Automated Recovery Boiler Sootblowing Control System
FUTURE RECOMMENDATIONS

Add Additional Sootblowing Sequences By Modifying The PLC
Code

Implement Smart Sootblowing By Implementing Advanced Control
Software in DCS Utilizing Instrumentation in DCS
2001 TAPPI PCE&I / ISA PUPID Joint Conference
March 27, 2001
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