Turbo Machinery Control by CCC Deetailed

Operation and Surge for Centrifugal Compressors

1. CCC CCC TurbomachineryTurbomachinery
Controls SystemControls System

2. Who is the CCC?Who is the CCC?Who is the CCC?
CCC is a CCC is a Controls CompanyControls Companydedicated to dedicated to
making the operation of Turbomachinery making the operation of Turbomachinery
SafeSafeand and EfficientEfficient
Safe = No Missed Commissioning
No Production Loss
Efficient = Minimum Power
The CCC Product is Control Solutions
Next

3. 1974 2008
?Offices Worldwide
?+/-400 Employees
?8300+ Installations
?200 Major Retrofit Projects/Year
?World’s Largest GT Retrofitter
In Operation 34 YearsIn Operation 34 Years
Next

4. MTBF of Series 3 Plus controllers is 43.4 years,
or 2.5 failures per million hours of operation
¾¾MultiMulti--loop controllers for speed, extraction, loop controllers for speed, extraction,
antisurge, & performance control antisurge, & performance control
¾¾Serial communications for peer to peer Serial communications for peer to peer
and host system communicationsand host system communications
Series 3+ ProductsSeries 3+ Products

5. Series 5 ProductsSeries 5 Products
Next

6. Vanguard Duplex ChassisVanguard Duplex Chassis
Power Supplies
IOC-555
MPU-750
Extended Card
Next

7. Series 5 Reliant DuplexSeries 5 Reliant Duplex
Switching
Module
Connector for
Remote
Switch Module
Status
Indicators
Manual
Switchover
Pushbuttons
Same
Electronics
Assembly and
Terminations
as Reliant SN
Next

8. GuardianGuardian
®®
Overspeed Trip SystemOverspeed Trip System
?API-670
Compliant
?2oo3 Voting
of Speed
Modules
?Redundant
Power
Supplies
?Hot-Swap
Speed
Modules
?Modbus
Comms
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9. VantageVantage
®®
Steam Turbine GovernorsSteam Turbine Governors
?Vantage GP
for API-611
General
Purpose
Turbines
?Vantage GD
for Generator
Drive
Turbines
?Local HMI for
Configuration
and
Maintenance
?Reliant in
an IP-54
Enclosure
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10. ?NEMA 4 enclosure
?Touch Screen Color
Graphics Operator Interface
–Parameter monitoring
–Alarms (visual and audible)
–Events and data logging
–Real-time trending of process
data
–Control loop tuning and
maintenance screens
–Remote network and web data
access
?Optional Instrumentation
and Value Packages
Air MiserAir Miser®®TL EnclosureTL Enclosure
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11. ¾¾Class 1, Div 2 / Class 1 Zone 2Class 1, Div 2 / Class 1 Zone 2
¾¾ATEX Group 2 Class 3ATEX Group 2 Class 3
¾¾Simplex or Simplex or ““hot backuphot backup””redundantredundant
¾¾All AOAll AO’’s have builts have built--in feedback loops to identify in feedback loops to identify
hardware or wiring problemshardware or wiring problems
Series 3++ ControllersSeries 3++ Controllers
¾¾OnOn--board temperature board temperature
monitoringmonitoring
¾¾OnOn--board power supply board power supply
voltage monitoringvoltage monitoring
¾¾Wired Ethernet versionWired Ethernet version
¾¾Completely backward Completely backward
compatible with S3+compatible with S3+

12. Raising the Bar Advanced Raising the Bar Advanced
Constraint ControlConstraint Control
¾¾UpstreamUpstream
improved control strategies for load sharing, expanders, improved control strategies for load sharing, expanders,
integration of networks across platformsintegration of networks across platforms
¾¾MidstreamMidstream
improved control strategies for Boil Off Gas networks, improved control strategies for Boil Off Gas networks,
intense focus on all primary LNG servicesintense focus on all primary LNG services
¾¾DownstreamDownstream
broader approach to process control, rather than just broader approach to process control, rather than just
Turbomachinery control. Advanced control strategies for Turbomachinery control. Advanced control strategies for
Ethylene, FCCU and PTA Plants. (Next focus is Ammonia). Ethylene, FCCU and PTA Plants. (Next focus is Ammonia).
Next

13. CCC Installations CCC Installations --IndonesiaIndonesia
¾¾PT. Pupuk PT. Pupuk IskandarIskandarMudaMuda
¾¾PT. Pupuk PT. Pupuk SriwidjayaSriwidjaya
¾¾PT. Pupuk PT. Pupuk KujangKujang
¾¾PT. Pupuk Kalimantan PT. Pupuk Kalimantan TimurTimur
¾¾PT. DSM PT. DSM KaltimKaltimMelamine IndonesiaMelamine Indonesia
¾¾PT. Amoco Mitsui PTAPT. Amoco Mitsui PTA
¾¾PT. PT. PolysindoPolysindoEkaEkaPerkasaPerkasa
¾¾PT. Chandra PT. Chandra AsriAsri
¾¾PertaminaPertamina/ Refinery (WGC / Refinery (WGC ExorExorProject)Project)
¾¾ConocoPhillipsConocoPhillipsIndonesiaIndonesia
¾¾ExxonMobilExxonMobilOil IndonesiaOil Indonesia
¾¾Total Total IndonesieIndonesie
¾¾PT. PT. KangeanKangeanEnergiEnergiIndonesiaIndonesia
¾¾BP BP TangguhTangguhLNGLNG
¾¾PT. PT. BadakBadakLNGLNG
¾¾PT. PT. ArunArunLNGLNG
¾¾PT. Indonesia Power (PLN)PT. Indonesia Power (PLN)
¾¾Etc.Etc.
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14. 1
PT
Section 1
outout
RSP
A
LSIC
Section 2
1A
UIC
1A
UICSerial
network
Train A
Next
Typical Single Train ControlsTypical Single Train Controls
(Suction Pressure Controls)(Suction Pressure Controls)
AntisurgeControls System
Performance Controls
System

15. Compressor RefresherCompressor Refresher
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16. Compressor TypeCompressor Type
Next
Compressors
Positive Displacement
Compressor
Dynamic Compressor
Reciprocating Compressor
Rotary Compressor
Membrane Compressor
Screw Compressor
Centrifugal
Axial
CCC FocusCCC Focus

17. Where do the different types of Where do the different types of
compressor fit?compressor fit?
Next

18. Types of Compressor Types of Compressor --Dynamic Dynamic
Compressors Compressors
Axial Compressor
Centrifugal Compressor
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19. Types of Compressor Types of Compressor --Dynamic Dynamic
Axial CompressorsAxial Compressors
Stator Blades
Rotor
Blades
Casing
Rotor Blades
Stator
Blades
Casing
Shaft
Next
Rotor
Stator

20. Cross section of axial compressorCross section of axial compressor
Compressor outlet nozzle
Rotor blades
Labyrinth seals
Guide-vane actuator linkageStator Blades
Compressor inlet nozzle
Thrust bearing
Adjustable guide vanes
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21. Barrel (Centrifugal)Barrel (Centrifugal) Bullgear (Centrifugal)Bullgear (Centrifugal)
Types of Compressor Types of Compressor ––DynamicDynamic
Centrifugal CompressorsCentrifugal Compressors
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22. Compressor inlet nozzle
Thrust bearing
Journal bearing
Shaft and labyrinth seal
Impeller inlet labyrinth sealsDischarge volutes
Impellers
Drive coupling
Casing
(horizontally split flange)
Compressor discharge nozzle
Horizontally Split Type (Centrifugal)Horizontally Split Type (Centrifugal)Horizontally Split Type (Centrifugal)
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23. Types of Compressor Types of Compressor --Picture of Picture of
Horizontally Split Type (Centrifugal)Horizontally Split Type (Centrifugal)
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24. Types of Compressor Types of Compressor --Principal of Principal of
Operation (Centrifugal)Operation (Centrifugal)
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25. Single-Section, Three-Stage Single-Case, Two-Section, Six-Stage
Types of Compressor Types of Compressor --ClassificationsClassifications
What is the function of this cooler?
I ntercoolingI ntercoolingreduces energy consumptionreduces energy consumption
but results in having multiple compressor mapsbut results in having multiple compressor maps
which need separate which need separate antisurgeantisurgeprotectionprotection
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26. Parallel Network
Two-Case, Two-Section, Six-Stage
Series Network
Types of Compressor Types of Compressor --ClassificationsClassifications
Next

27. Why Compressor SurgeWhy Compressor Surge
……and what happens and what happens
when they dowhen they do
Next
Surge PhenomenonSurge Phenomenon

28. ?From A to B…….20 - 50 ms…………….. Drop into surge
?From C to D…….20 - 120 ms…………… Jump out of surge
?A-B-C-D-A……….0.3 - 3 seconds……… Surge cycle
Q
s, vol
P
d
Machine shutdown
no flow, no pressure
?Electro motor is started
?Machine accelerates
to nominal speed
?Compressor reaches
performance curve
Note: Flow goes up faster
because pressure is the
integral of flow
?Pressure builds
?Resistance goes up
?Compressor “rides” the curve
?P
d
= P
v
+ R
losses
P
d
= Compressor discharge pressure
P
v
= Vessel pressure
R
losses
= Resistance losses over pipe
Developing the surge cycle on the Developing the surge cycle on the
compressor curvecompressor curve
P
d
P
v
R
losses
B A
C
D
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29. ¾¾Rapid flow oscillations Rapid flow oscillations
¾¾Thrust reversalsThrust reversals
¾¾Potential damagePotential damage
FLOW
PRESSURE
TEMPERATURE
TIME (sec.)
1 2 3
TIME (sec.)
1 2 3
TIME (sec.)
1 2 3
Major Process Parameters during Major Process Parameters during
SurgeSurge
?Rapid pressure
oscillations with
process instability
?Rising temperatures
inside compressor
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30. Some surge consequencesSome surge consequences
¾¾Unstable flow and pressureUnstable flow and pressure
¾¾Damage in sequence with increasing Damage in sequence with increasing
severity to seals, bearings, impellers, severity to seals, bearings, impellers,
shaftshaft
¾¾Increased seal clearances and leakage Increased seal clearances and leakage
¾¾Lower energy efficiencyLower energy efficiency
¾¾Reduced compressor lifeReduced compressor life
Next

31. Factors leading to onset of Factors leading to onset of
surgesurge
¾¾StartupStartup
¾¾ShutdownShutdown
¾¾Operation at reduced throughputOperation at reduced throughput
¾¾Operation at heavy throughput with:Operation at heavy throughput with:
--TripsTrips
--Power lossPower loss
--Operator errorsOperator errors
--Process upsetsProcess upsets
--Load changesLoad changes
--Gas composition changesGas composition changes
--Cooler problemsCooler problems
--Filter or strainer problemsFilter or strainer problems
--Driver problemsDriver problems

32. Standard Antisurge Standard Antisurge
Control Vs CCC Controls Control Vs CCC Controls
SystemSystem
Next

33. Flow
Pressure
minimum speed
maximum speed
surge limit
stonewall or
choke limit
power limit
process limit
stable zonestable zone
of operationof operation
adding control
margins
Actual available
operating zone
CCC Business in Constraint ControlCCC Business in Constraint Control
Next

34. Flow
Pressure
minimum speed
maximum speed
surge limit
stonewall or
choke limit
power limit
process limit
stable zonestable zone
of operationof operation
adding control
margins
Actual available
operating zone
CCC Business in Constraint ControlCCC Business in Constraint Control
Next

35. Expanding the Operating EnvelopeExpanding the Operating Envelope
Operating Point
Limit
Operating Point
Setpoint
Base Ingredients:
-Advanced algorithms
-Rate of change feed forward signals
-Fast hardware
Limit
Setpoint
General
Purpose
Control
CCC
Control
Next

36. Standard Antisurge ControlStandard Antisurge Control
1
UIC
CompressorCompressor
1
FT
1
P
sT
ProcessSuction
1
P
dT
Next
Antisurge
Controller
Recycle Valve

37. Conventional Control Using Separate Conventional Control Using Separate
Performance RecyclePerformance Recycle
CompressorCompressor
ProcessSuction
1
UI
C
1
F
T 1
P
sT
1
P
dT
1
PIC
Next
Conventional
Capacity/ Performance
Controller
Additional Recycle Valve

38. Why Invest in Advanced Why Invest in Advanced
Controls?Controls?
Next

39. How Will CCC How Will CCC ControlControl??
¾¾Antisurge Control?Antisurge Control?
¾¾Capacity Control?Capacity Control?
Next

40. CCC Controls SystemCCC Controls System
Next
1
UIC
VSDS
Compressor
1
FT
1
P
sT
1
T
sT
Process
Suction
1
P
dT
1
T
dT
1
ST
1
PIC
1
HIC
Load
Serial
network
Antisurge
Controller
Performance
Controller

41. Control System ObjectiveControl System Objective
Control System Objectives:Control System Objectives:
¾¾The control system objective is to keep the The control system objective is to keep the
process on its Primary Process Variable (PV) process on its Primary Process Variable (PV)
setset--point, and to return it to setpoint, and to return it to set--point as quickly point as quickly
as possible after a process disturbanceas possible after a process disturbance
¾¾The control system has to keep the process The control system has to keep the process
on/return to seton/return to set--point while operating within point while operating within
compressor operating envelope limits, including compressor operating envelope limits, including
protection against surge and surge damageprotection against surge and surge damage
Next

42. Challenges of Compressor Challenges of Compressor
Control SystemControl System
The ingredients of a successful compressor control systemThe ingredients of a successful compressor control system
are:are:
zzAn algorithm that can accurately locate the operating point An algorithm that can accurately locate the operating point
and its corresponding surge limitand its corresponding surge limit
zzA controller execution speed that will allow a digital controlleA controller execution speed that will allow a digital controller r
to emulate immediate analog controlto emulate immediate analog control
zzControl responses that allow different margins of safety for Control responses that allow different margins of safety for
different operating conditionsdifferent operating conditions
zzAdvanced control strategies that can avoid the negative Advanced control strategies that can avoid the negative
effects of loop interactioneffects of loop interaction
zzA quick acting, correctly sized antisurge control valveA quick acting, correctly sized antisurge control valve
zzThe elimination of unnecessary dead time or lag time within The elimination of unnecessary dead time or lag time within
the systemthe system
zzValid load sharing strategiesValid load sharing strategies
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43. Standard Control VS CCC Standard Control VS CCC
ControlsControls
¾¾StandardStandard ¾¾CCCCCC
Next
1
U
I
C
VSDS
Compressor
1
F
T
1
P
s
T
1
T
s
T
Process
Suction
1
P
d
T
1
T
d
T
1
S
T
1
P
I
C
1
H
I
C
Load
Serial
network
CompressorCompressor
ProcessSuction 1
U
I
C
1
F
T
1
P
s
T
1
P
d
T
1
P
I
C

44. Standard Control VS CCC Standard Control VS CCC
ControlsControls
¾¾StandardStandard
zz15% surge margin15% surge margin
zzQuick opening valvesQuick opening valves
zzNo control of process No control of process
variable via recyclevariable via recycle
zzNo invariant coordinatesNo invariant coordinates
zzConcentrating on Concentrating on
‘‘ProtectionProtection’’
¾¾CCCCCC
zzTypically 8% surge marginTypically 8% surge margin
zzLinear valves with Linear valves with
positioners for control positioners for control
across 100% rangeacross 100% range
zzControl of primary process Control of primary process
variable by recycle when variable by recycle when
speed limit is reachedspeed limit is reached
zzCan handle varying Can handle varying
molecular weight gasesmolecular weight gases
zzConcentrating on Concentrating on ‘‘Control Control
and Protectionand Protection’’
Next

45. CCC CCC ControlController protectionler protection
How CCC How CCC AntisurgeAntisurgeController Controller
protects compressor against protects compressor against
surge?surge?
Next

46. 1
UIC
VSDS
Compressor
1
FT
1
P
sT
1
P
dT
?The antisurge controller UIC-1 protects the compressor
against surge by opening the recycle valve
DischargeSuction
R
c
q
r
2
R
process
R
process+valve
Antisurge Controller Operation Protection #1 Antisurge Controller Operation Protection #1
The Surge Control Line (SCL)The Surge Control Line (SCL)
Next

47. A
R
c
B
¾¾When the operating point When the operating point
crosses the SCL, PI crosses the SCL, PI
control will open the control will open the
recycle valverecycle valve
¾¾PI control will give PI control will give
adequate protection for adequate protection for
small disturbancessmall disturbances
SLL = Surge Limit Line
SCL = Surge Control Line
q
r
2
Antisurge Controller Operation Protection #1 Antisurge Controller Operation Protection #1
The Surge Control Line (SCL)The Surge Control Line (SCL)
?PI control will give stable control during steady state
recycle operation
?Slow disturbance example
Next

48. A
Rc
B
? When the operating point
moves quickly towards the
SCL, the rate of change
(dS/dT) can be used to
dynamically increase the surge
control margin.
? This allows the PID controller
to react earlier.
? Smaller steady state surge
control margins can be used
w/o sacrificing reliability.
? Fast disturbance example
Q
2
Antisurge Controller Operation Protection #2 Antisurge Controller Operation Protection #2
Moving The Surge Control Line (SCL)Moving The Surge Control Line (SCL)
SLL = Surge Limit Line
SCL = Surge Control Line
Next

49. Antisurge Controller Operation Protection #3 Antisurge Controller Operation Protection #3
The Recycle TripThe Recycle Trip
®®
LineLine((RTLRTL))
Benefits:
–Reliably breaks the
surge cycle
–Energy savings due to
smaller surge margins
needed
–Compressor has more
turndown before
recycle or blow-off
–Surge can be
prevented for virtually
any disturbance
SLL = Surge Limit Line
RTL = Recycle Trip Line
SCL = Surge Control Line
Output
to Valve
Time
Open-loop Response
PI Control Response
PI Control Step Change
+
To antisurge valve
Total Response
Rc
Q
2
OP
Next

50. After time delay CAfter time delay C
22controller checks if Operating Point is back to controller checks if Operating Point is back to
safe side of safe side of Recycle TripRecycle Trip
®®
LineLine
--If If YesYes: Exponential decay of : Exponential decay of Recycle TripRecycle Trip
®®
responseresponse..
Output
to valve
Time
One step response
PI Control
Recycle Trip
®
Total
100%
0%
C
2
Multiple step response
Output
to valve
Time
PI Control
Recycle Trip
®
Total
C
2
C
2
C
2
What if one Recycle TripWhat if one Recycle Trip
®®
step step
response is not enough?response is not enough?
-If No: Another step is added to the Recycle Trip
®
response.
Next

51. Output to
Recycle Valve
Input
Output to
Turbine ValveSpeed InputsSpeed Inputs
Antisurge InputsAntisurge Inputs
Process Variable InputsProcess Variable Inputs
Serial
Communication
Link CCC-DCS
Flow
Pressure
Temperature
Gas Data
(Field
Transmitter)
Next
Integrated control Decoupling of Integrated control Decoupling of
Performance and Performance and AntisurgeAntisurgecontrolcontrol

52. ∆P
o
PIC-SP
R
c
P
s
SLL
SCL
AC
B
Integrated control Decoupling of Integrated control Decoupling of
Performance and Performance and AntisurgeAntisurgecontrolcontrol
2. 2. The decoupling control starts to actThe decoupling control starts to act
Performance control send request Performance control send request
to increase speedto increase speed
3. 3. The speed increasing combined with The speed increasing combined with
antisurgeantisurgevalve opening, then,valve opening, then,
The trace of operating line as shownThe trace of operating line as shown
4. 4. The net control effect is more The net control effect is more
stable operation even with large stable operation even with large
process disturbanceprocess disturbance
5. 5. This decoupling control is can This decoupling control is can
reduce the control safety margin, reduce the control safety margin,
Therefore it can achieve energy Therefore it can achieve energy
saving and safe operationsaving and safe operation
1. When operating at Point A, process 1. When operating at Point A, process
encounters a large disturbance,encounters a large disturbance,
operating point will move to Point Boperating point will move to Point B
Next

53. Antisurge Controller Operation Antisurge Controller Operation
Protection #4 Protection #4 ““Safety OnSafety On””
How about if the protection not capable How about if the protection not capable
against surge?against surge?
Compressor has real surgeCompressor has real surge
What will CCC controller do?What will CCC controller do?
Next

54. SCL = Surge Control Line
?If Operating Point crosses the Safety
On
®
Linethe compressor is in surge
SLL = Surge Limit Line
RTL Line = Recycle Trip
®
?The Safety On
®
response shifts the
SCLand the RTL to the right
New SCL
New RTL
?Additional safety or surge margin is
added
Additional surge margin
?PI control and Recycle Trip
®
will
stabilize the machine on the new SCL
SOL = Safety On
®
Line
Pressure axis
Flow axis
Antisurge Controller Operation Protection #5 Antisurge Controller Operation Protection #5
““Safety OnSafety On””
Next

55. CCC CCC
LOAD SHARING CONTROLS LOAD SHARING CONTROLS
SYSTEMSYSTEM
Next

56. ¾¾Compressors are often operated in parallel and sometimes in seriCompressors are often operated in parallel and sometimes in serieses
¾¾The purposes of networks include:The purposes of networks include:
zzRedundancyRedundancy
zzFlexibilityFlexibility
zzIncremental capacity additionsIncremental capacity additions
¾¾Often each compressor is controlled, but the network is ignoredOften each compressor is controlled, but the network is ignored
¾¾Compressor manufacturers often focus on individual machinesCompressor manufacturers often focus on individual machines
¾¾A A ““network viewnetwork view””of the application is essential to achieve good of the application is essential to achieve good
surge protection and good performance control of the network.surge protection and good performance control of the network.
Compressor networksCompressor networks
Next

57. Control system objectives for compressors in parallel:Control system objectives for compressors in parallel:
zzMaintain the primary performance variable (in this case Maintain the primary performance variable (in this case
suction pressure), and then:suction pressure), and then:
zzOptimally divide the load between the compressors in the Optimally divide the load between the compressors in the
network, while:network, while:
??Minimizing risk of surgeMinimizing risk of surge
??Minimizing energy consumptionMinimizing energy consumption
??Minimizing disturbance of starting and stopping Minimizing disturbance of starting and stopping
individual compressorsindividual compressors
??Operating within limitsOperating within limits
Load SharingLoad Sharing
Next

58. Load Sharing Control system types:Load Sharing Control system types:
1. Base and Swing Load Sharing system1. Base and Swing Load Sharing system
2. Equal Flow Load Sharing system2. Equal Flow Load Sharing system
3. CCC Equidistance Load Sharing controls system3. CCC Equidistance Load Sharing controls system
Load SharingLoad Sharing
Next

59. Process
PIC
1
1
UIC
VSDS
Compressor 1
2
UIC
VSDS
Compressor 2
HIC
1
Suction
header
Swing
machine
Base
machine
Notes
?All controllers act
independently
?Transmitters are
not shown
Base and Swing Load SharingBase and Swing Load Sharing
Flow Diagram for Control ProcessFlow Diagram for Control Process
Next

60. R
c,1
q
r,1
2
R
c,2
q
r,2
2
Compressor 1 Compressor 2
PIC-SP
Swing machine Base machine
Q
C,2
=Q
P,2
Q
C,1
Q
P,1
where:
Q
P
= Flow to process
Q
C
= Total compressor flow
Q
C
-Q
P
= Recycle flow
Q
P,1
Q
P,1 +Q
P,2=Q
P,1 +Q
P,2
Notes:
?Base loading is inefficient
?Base loading increases the risk of surge
since compressor #1 will take the worst
of any disturbance
?Base loading requires frequent operator
intervention
?Base loading is NOTrecommended
Base and Swing Load Sharing Base and Swing Load Sharing
Parallel Compressor ControlParallel Compressor Control
Q
P,2
Next

61. Process
PIC
1
1
UIC
Compressor 1
VSDS
Compressor 2
Suction
header
Notes
?Performance controllers
act independent of
antisurge control
?Higher capital cost due to
extra Flow Measurement
Devices (FMD)
?Higher energy costs due
to permanent pressure
loss across FMD’s
1
FIC
2
FIC
2
UIC
outout
out
RSPRSP
RSPRSP
RSPRSP
outout
RSPRSP
Equal Flow Load sharingEqual Flow Load sharing
Flow Diagram for Control ProcessFlow Diagram for Control Process
VSDS
Next

62. Notes:
?Requires additional capital investment in
FMD’s
?Requires additional energy due to
permanent pressure loss across FMD’s
?Poor pressure control due to positive
feedback in control system (see next)
?Equal flow division is NOTrecommended
R
c,1
q
r,1
2
R
c,2
q
r,2
2
PIC-SP
Q
P,1
Q
P,2
Q
C,2
Equal flow Equal flowQ
P,1 =Q
P,2
Equal Flow Load sharingEqual Flow Load sharing
Parallel Compressor ControlParallel Compressor Control
Compressor 1 Compressor 2
where:
Q
P
= Flow to process
Q
C
= Total compressor flow
Q
C
-Q
P
= Recycle flow
Next

63. Notes
?All controllers are
coordinating
control responses
via a serial network
?Minimizes recycle
under all operating
conditions
Process
1
UIC
VSDS
Compressor 1
VSDS
Compressor 2
Suction
header
1
LSIC
2
UIC
out
RSP
Serial
network
out
RSP
2
LSIC
1
MPIC
Serial
network
Serial
network
CCC Equidistance Load sharingCCC Equidistance Load sharing
Flow Diagram for Control ProcessFlow Diagram for Control Process
Next

64. PIC-SP
0.1
0.2
0.3
DEV = 0
0.1
0.2
0.3
DEV
1
DEV
2
SCL = Surge Control Line
R
c,1
q
r,1
2
R
c,2
q
r,2
2
Compressor 1 Compressor 2
Dev
1
= Dev
2
Q
1
=Q
2
N
1
= N
2
Notes:
?Maximum turndown (energy savings) without recycle or blow-off
?Minimizes the risk of surge since all machines absorb part of the
disturbance
?Automatically adapts to different size machines
?CCC patented algorithm
CCC Equidistance Load sharingCCC Equidistance Load sharing
Parallel Compressor ControlParallel Compressor Control
Next

65. Loop
Decoupling
FA
Mode
PI
Loop
Decoupling
+
Analog Inputs
+
DEV
To antisurge valve To performance
control element
PID
Load
balancing
PV
PV
SP
Primary
response
DEV DEV
DEV
DEV from other
loadsharing
controllers
Primary
response
Average
SP
The load balancing responseThe load balancing response
Loadsharing Loadsharing
ControllerController
Antisurge Antisurge
ControllerController
Master
Controller
RT
Next

66. CCC LOAD SHARINGCCC LOAD SHARING
Control System DrawingControl System Drawing
Next
MASTER CONTROLLER
(Suction Header Controls)
LOAD SHARING CONTROLLER
ANTISURGE CONTROLLER

67. End SlidesEnd Slides
Thank You very much for your Thank You very much for your
kind attention and cooperationkind attention and cooperation
PT Putranata Adi Mandiri
Jl Kartini VIII No. 9
Jakarta 10750
Tel: [phone]
Fax: [phone]
Email: [email protected]