040220222245Modifications_Major work TG_SG Side OH Unit_1.pdf

YOKOGAWA DCS SYSTEM CENTUM CS3000 at ₹ 1500000 | PLC Panel in Chennai | ID: 2853484495133

1. SIMHADRI
Unit-1 O/H: Modifications/Major Works in TG/SG (C&I)

2. 5
2
3
4
1
Conversion of BFP R/C valve from
ON/OFF to continuous control type
Development and testing of LPBP
EHC coil to overcome obsolescence
Replacement of UPS Battery Bank
Up-gradation of TSI server
Boiler Emergency Trip from MMI
made available
2
Contents
10
7
8
9
6
BECK make actuators Installation in
PA fan Blade Pitch
PA fan bearing temperature/Vib
protection made 2/3
Modifications in PA header
pressure protection/control
ID Fans Lube oil flow meter
installation
MILL-C, E inertingsteam valves
remote operation

3. Modification in BFP Recirculation Control Scheme
❑ProblemBeingFaced:Difficultyindrumlevel
controlduringUnitpartloadoperationduetoauto
closing/openingofBFPR/Cvalves.
❑CommunicationissuedbyCOSformodificationof
BFPR/CcontrolvalvefromON-OFFtomodulatingtype
for17units.
❑Proposedmodificationdiscussedinternally,and
issuetakenupwithOEM(M/SMasoneilian)for
modalitiesofmodification.
❑Inthenewermodel51typeactuator,smart
positionermountingandmodificationinpneumatic
circuitwasrequired.

4. Modification in BFP Recirculation Control Scheme
▪InitiallyVendorinadvertentlysuggestedthatsingle
actingpositionerneedtobeinstalledbutafterdrawing
studyatsite,itwasfoundthatdoubleactingpositioner
isrequiredandsamewaslaterconfirmedbyOEM.
▪PRforsmartpositionercreatedbutafterfollowupit
wasestimatedthatthematerialwillnotbereceived
timely.
▪DecidedtouseSiemensmakeSIPARTpositioner
(alreadybeingusedatsite)readilyavailableinstore.
▪Modificationinpneumaticcircuitdonewithhelpof
OEMrepresentativevisitingforTMDwork,Solenoids
anddoubleexhaustvalvesusedinpneumaticcircuitto
ensurefastclosing.

5. New Implemented Logic : Modification in BFP R/C
5
▪Solenoidvalvewill
operateincondition
ofautoorprotection
open/closecondition
toensurefast
operation.
▪Inbetweenthese
conditions,modulating
operationofvalve
willensurerequired
flowasperprovided
curve.

6. Development and testing of LPBP EHC coil
❑ProblemBeingFaced:Obsolescenceof
LPBPEHCsystemPAN-NTPC,nosupportfrom
OEM/OES.
❑Mostvulnerable/failurepronepartbeinglooked
afterC&IinEHCsystemisEHCcoil.
❑NostockofEHCblockorEHCcoilatsite.
ManysitesincludingSimhadri,Vindhyachal,
Farakka,Kahalgaon,Korbafacingthesame
issue.
❑VeryhighcostbeingdemandedbyVendorsfor
upgradtion/modificationofthesystem.Majorof
thepartofLPBPEHCpertainstoTMD.

7. Development and testing of LPBP EHC coil
▪CollaborationdonewithalternativevendorM/S
Iyappan (Vendor already supplying
materials/servicesforHPBypass)fordevelopment
oftheEHCcoil.
▪ThreedifferentcoilsweresequentiallytestedinLab
conditionandrejected.Fourthonewasfound
workingsatisfactorily.
▪CoilinstalledduringUnit-1Overhauling,keptin
servicefor7daysandfoundokaftercheckingits
operationseveraltimes.
▪Coilkeptasbackupspare,informationsharedwith
othersites.
Complete EHC and protection system also developed
by M/S Iyappan.

8. Replacement of UPS Battery Bank
❑ProblemBeingFaced:BatteryBankactualcapacity
foundlimitedto80-85%oftheratedcapacity.
❑Aspercorporateguidelines,itwasdecidedtoreplace
thebatterybankaftercompletionof10yearsofservice.
❑PO:4000255901placedtoM/sSAFTINDIAPVTLTDfor
supply,supervisionandcommissioningofnewbatterybank
aswellasbuy-backofoldbatteries.
❑Specificationofnewbatterybank:
•NickelCadmiumHighDischargeBattery.
•295cellsofKPH353AH
•Nominalvoltage:1.2V,FloatVoltage:1.42-1.45
❑100%ratedcapacityattainedwithnewlyinstalledbattery
bank.

9. Up-gradation of TSI server
❑ProblemBeingFaced:Existingservercrashedandwasnotavailableanymore.NosupportfromOEM
fortheissueastheserverandsoftwarewerereportedobsolete.
❑DuetounavailabilityofTSIserver,noanalysisofvibrationpatternswaspossibleduringany
abnormality.
❑PO4000259279placedtoOEM(GEOILANDGASINDIAPVTLTD)forsupplyoflatestSystem-1
Serverformonitoring,analyzing&diagnosticpurpose.
❑System-1EVO(version21.1SP1)installedinServer,existing3500/20(RIMmodule)andunsupported
monitoringcards(3500/42M)replacedwithnewTDImodule(3500/22)andsupportingmonitoringcards.

10. Up-gradation of TSI server
❑ExistingrackupandModfile
downloadedto3500rackand
configurationsretrieved.
❑Machinetraindiagram,graphics,
trendsconfiguredatsiteasperP&ID.
❑TSIremotedisplayPCprovidedin
controlroom(keptnearfiresystem
PC).
❑On-sitetrainingimpartedbyOEM
representativetoNTPCandassociate
staffs.

11. Boiler
Emergency Trip
from MMI
Earlier Disabled due to spurious
tripping
Put back in service after HMI
Upgradation
Logic disabled in Individual MFT
Processor, Now restored
Checked during Boiler P&I Checking

12. BECK make actuators
Installation
•Earlier AumaMake -Dead
band & Hunting issue,
Difficult to calibrate
•Beck make actuator
offers fine control and
easy to calibrate

13. PA fan
bearing
temperature
protection
Earlier single point protection led to spurious tripping
in case of malfunction of RTD or TT
Additional 8 RTDs installed in 04 bearings-02 in each
along with 01 existing one
Protection logic changed to 2/3
New Temperature points & LVMs are in 1.0E and 1.0F
controller for PA fan A & B respectively
Digital contact output to individual PA fan Panel
2/3 logic in existing panel.

14. PA fan and motor
vibration
protection made
2/3
Earlier single point protection led to spurious tripping in
case of malfunction of Vibration
Additional 12 loop powered Vibration Probes installed with
existing probes
Protection logic changed to 2/3
New Vibration points & LVMs are in 1.0E and 1.0F
controller for PA fan A & B respectively
Digital contact output to individual PA fan Panel
2/3 logic in existing panel.

17. MRHS JB
Modification

18. PA header
pressure
protection
modification
•Earlier 03 Pressure switch for Very Low and 02 Pressure switch
for Lo

19. Current Bias Selection Disabled in PA Header Pressure
Control
Unit 2 tripped due
to malfunction of
Current bias logic in
PA Hdr Pr control
In Unit 1 Current
Bias selection
Disabled in line
with Unit 2

20. ID Fans Lube
oil flow
meter
installation

21. MILL-C, E inerting steam valves remote operation
Remote Operation
already made through
from C&I Side before
Upgradation
Electrical Actuator
Limit switch setting
pending from
Electrical
Existing tiles of PAPH
FG inlet gate Blowers
used for Inerting
steam Actuator

22. ThankYou
Questions ?