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NTPC/VINDHYACHAL
UNIT OVERHAULS
6X210 MW & 4X500 MW UNITSOF
VINDHYACHAL SUPER THERMAL POWER PROJECT,
NATIOANAL THERMAL POWER CORPORATION LTD.,P.O. : VINDHYANAGAR, DISTT.: SIDHI (M.P.), PIN:486885
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NTPC/VINDHYACHAL
UNIT OVERHAULS PHILOSOPHY
210 MW ( LMW ) UNITS
TYPE OF OVERHAUL MAIN AREAS IDENTIFIED PERIOD OF FREQUENCY
FOR OVERHAUL OVERHAUL
A BOILER & AUX. 20 DAYS EVERY YEAR
TUR. BRGS. INSP.
X BOILER & AUX. 21 DAYS EVERY 3rd YEAR
GENERATOR ROTOR THREAD OUT
D BOILER & AUX. 35 DAYS EVERY 6th YEAR
ALL TURBINE CYLINDERS O/H
GENERATOR ROTOR THREAD OUT
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NTPC/VINDHYACHALUNIT OVERHAULS PHILOSOPHY
500 MW ( KWU ) UNITS
TYPE OF OVERHAUL MAIN AREAS IDENTIFIED PERIOD OF FREQUENCY
FOR OVERHAUL OVERHAUL
E BOILER & AUX. 15 DAYS EVERY YEARTUR. BRGS. INSPECTION
F BOILER & AUX. 25 DAYS EVERY 3rd YEAR
LP TURBINE INSPECTION
G BOILER & AUX. 35 DAYS EVERY 8th YEAR
HPT / IPT O/H
GENERATOR ROTOR THREAD OUT
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NTPC/VINDHYACHAL
UNIT OVERHAULS - PHILOSOPHY
210 MW ( LMZ ) UNITS
TO CONTROL THE O&M COST FOLLOWING ARE THE ACTIONS:
SEQUENCE OF O/H FOR THE STATION ARE SO ADJUSTEDTHAT NOT MORE THAN TWO MAJOR O/Hs (TYPE D)
TAKEN UP IN A YEAR.
WHENEVER TWO MAJOR O/H COMMENCES IN A STATION
IN A YEAR, SITE TAKES DECISION, DEPENDING ON BOILERCONDITIONS, TO RESTRICT THE O/H DURATION OF BOILER
SUITABLY TO 17 DAYS AND 15 DAYS FOR 200 MW AND 500
MW UNITS RESPECTIVELY.
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NTPC/VINDHYACHAL
OBJECTIVES OF UNIT OVERHAULS
TO MAXIMIZE PLANT AVAILABILITY
TO MINIMIZE MAINTENANCE COST THROUGH
OPTIMIZATION OF RESOURCE UTILIZATION
TO CREATE SAFETY IN WORK, EQUIPMENT AND
ENVIRONMENT
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NTPC/VINDHYACHAL
AIMS OF UNITS OVERHAUL
TO IMPROVE AVAILABILITY OF EQUIPMENT & SYSTEM
TO IMPROVE QUALITY & INSPECTION OF MAINTENANCE JOBS
TO IMPROVE MONITORING & REPORTING OF O/H PROGRESS
TO REDUCE OVERHAUL DURATION
TO IMPROVE THE RE-COMMISSIONING INTERFACE
TO PROVIDE A RECORD OF WORK CARRIED OUT
TO MINIMIZE ISOLATION RESTRICTIONS
TO REDUCE DUPLICATION OF ENGINEERING EFFORTS TO ENSURE STATUTORY REQUIREMENT OF BOILER LICENCE
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NTPC/VINDHYACHAL
CATEGORIZATION OF
UNIT OVERHAUL PROCESS
PLANNING
UNIT SHUT DOWN COOLING DOWN OF MACHINES
DISMANTLING
INSPECTION FOR CONDITION
REPAIR & RECTIFICATION
ASSEMBLY
TESTING & INSPECTION
REVIVAL OF EQUIPMENT & SYSTEM
REVIVAL & RECOMMISSIONING OF UNIT
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NTPC/VINDHYACHAL
IMPROVEMENT AREAS IDENTIFIED
BARRING GEAR STOPPAGE TIME CONDENSER VACUUM GENERATOR AIR TIGHTNESS TEST TIME AIR INGRESS IN BOILER
SCOPE OF WORK OF GENERATOR OVERHAUL ELECTRICAL TESTING TIME REVIVAL TIME OF UNIT AFTER UNIT OVERHAUL-HFO
CONSUMPTION SCOPE OF IN SITU TESTS DURING UNIT OVERHAUL SCAFFOLDING ERECTION & DISMANTLING TIME PERCENTAGE AREA OF TUBES COVERED FOR D-METERING BOILER SAFETY VALVES SETTING TIME
ULTIMATELY LEADING TO IMPROVEMENT IN PLANT
AVAILABILITY, RELIABILITY & REDUCTION OF O&M COST
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NTPC/VINDHYACHAL
PLANNING OF UNIT OVERHAULS
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NTPC/VINDHYACHAL
CLASSIFICATION OF PLANNING ACTIVITIES
PRE OVERHAUL ACTIVITIES
DURING OVERHAUL ACTIVITIES
POST OVERHAUL ACTIVITIES
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NTPC/VINDHYACHAL
PRE OVERHAUL ACTIVITIES
PLANNING & APPROVAL OF EIGHT YEAR ROLLING PLAN
OF UNIT OVERHAULS
PLANNING & APPROVAL OF NEXT FINANCIAL YEAR PLANFOR UNIT OVERHAULS
PLANNING & APPROVAL OF MAJOR WORKS TO BE
CARRIED OUT DURING UNIT OVERHAULS
IDENTIFICATION, REQUIRED QUANTITY PROJECTIONAND REVIEW OF STATUS OF CONSUMABLES ( STOCK
ITEMS) ON MONTHLY BASIS FOR UNIT OVERHAULS
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NTPC/VINDHYACHAL
CONTD
IDENTIFICATION OF CRITICAL MATERIALS REQUIRED
FOR UNIT OVERHAULS AND REVIEW ON MONTHLY BASIS.
PREOVERHAUL MEETING FOR REVIEW OF CONSTRAINTS& PREPAREDNESS INVOLVING ALL.
PRE OVERHAUL CONDITION MONITORING REPORT
PREOVERHAUL UNIT SURVEY
UNIT OUTAGE ANALYSIS FROM LAST OVERHAUL
FEED BACK OF UNIT FROM FIRST SYNCHRONIZATION
REVIEW OF STATUS & COORDINATION OF WELDING
SUPPLY, LIGHTING, LIFTS, HOISTS, CRANES ETC.
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NTPC/VINDHYACHAL
CONTD
PAST OVERHAULS AT A GLANCE (HISTORY OF UNITS)
PREPARATION OF MILESTONES (PLANNED)
COMPILATION OF UNIT DEFECT LIST
PRE OVERHAUL SPRAY VALVES CHARACTERISTICS
WORK REQUIRED TO BE CARRIED OUT AS PER
OPERATION REQUIREMENT
EFFICIENCY REQUIREMENT
CHEMISTRY REQUIREMENT
TRIPPING COMMITTEE RECOMMENDATIONS
C&I REQUIREMENT
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NTPC/VINDHYACHAL
CONTD
BOILER TUBE LEAKAGE COMMITTEE RECOMMENDATIONS
OS RECOMMENDATIONS
CONDITION MONITORING GROUP RECOMMENDATIONS
SAFETY REQUIREMENT
R&M REQUIREMENT
PREPARATION OF: PTW & CLEARANCE BOOKS FOR BOILER & AUX.
PTW & CLEARANCE BOOKS FOR TG & AUX.
CLEARANCE & RECOMMISSIONING BOOK FOR VALVES,
DAMPERS, IGVs, SOOT BLOWERS & LRSBS
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NTPC/VINDHYACHAL
CONTD...
CHECK SHEET FOR MOTOR TRIALS, EQUIPMENT
RECOMMISSIONING & PROTECTION CHECKING
CHECK SHEET FOR VALVES REQUIRED FOR CONDENSER
FLOOD TEST
CHECK SHEET FOR VALVES REQUIRED FOR BOILER
HYDRO TEST
COMMUNICATION LOG BOOK
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NTPC/VINDHYACHAL
DURING OVERHAUL ACTIVITIES
PREPARATION OF DISPLAY BOARD FOR
COMMUNICATION OF OVERHAUL PLANNING
COORDINATION IN ISSUE OF PERMITS
MONITORING OF WORK PROGRESS / COMPLETION
COORDINATION OF REGULAR UNIT OVERHAUL MEETING
AT 5:30 PM IN O&M CONFERENCE HALL
PREPARATION & DISTRIBUTION OF RECORD NOTES
FEEDBACK TO WRHQ & CC-OS FOR WORK PROGRESS
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NTPC/VINDHYACHAL
MONITORING & REVIEW OF CRITICAL VALVES STATUS AS
PER CHECK SHEETS REQUIRED FOR CONDENSER FLOOD
TEST & BOILER HYDRO TEST
MONITORING & REVIEW OF CLEARANCES AVAILABLE &
RECOMMISSIONING PROGRESS ( MOTORS TRIALS /
EQUIPMENT TRIALS)
COORDINATION IN
FURNACE AIR TIGHTNESS TESTS
CONDENSER FLOOD TESTS
BOILER HYDRO TESTS
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NTPC/VINDHYACHAL
POST OVERHAUL ACTIVITIES
PREPARATION OF UNIT-WISE UNIT OVERHAUL REPORTIN BOOK FORM HARD COPY FOR LIBRARY & ISO
PREPARATION OF UNIT OVERHAUL REPORT IN CD-
FORMAT POST OVERHAUL REVIEW OF WORKS PLANNED AND
ACTUALLY COMPLETED.
POST OVERHAUL REVIEW OF IMPROVEMENT IN
PARAMETERS & EFFICIENCY POST OVERHAUL PLAN Vs ACTUAL DEVIATION SHEET
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NTPC/VINDHYACHAL
PROCESS IMPROVEMENTS
BOILER EXTERNAL WATER WASHING WAS CAUSINGDAMAGE TO INSULATION AND DELAY IN START OFOVERHAUL ACTIVITIES, DRY BOILER CLEANINGSTARTED.
QUICK ERECT SCAFFOLDING IS BEING USED FOR BOILERINTERNAL CLEANING & INSPECTION
HIGH PRESSURE WATER JET CLEANING IS BEING DONEFOR BOILER TUBES
ALL PA FANS & MILL MOTORS VIBRATION MEASUREMENTALSO STARTED DURING UNIT OVERHAULS
ALL HT MOTORS TRIAL RUN IS BEING TAKEN FOR 8 HRSAND LT MOTORS FOR 4 HRS
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NTPC/VINDHYACHAL
PROCESS IMPROVEMENTS
CONDENSER TUBE CLEANING IS BEING DONE USINGCONCO BULLETS
INVOLVEMENT OF FQA IS INCREASED IN MAIN TURBINE &GENERATOR AREA
BOILER DRUM FILLING USING HOT WATER STARTED
BOILER TUBES D-METERING SCOPE INCREASED UPTO25000 LOCATIONS.
24-VOLT HAND LAMPS ARE BEING USED
PREOVERHAUL / DURING OVERHAUL SAFETY SURVEYBEING CARRIED OUT
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NTPC/VINDHYACHAL
ADDITIONAL RESPONSIBILITIES
DRAWING SECTION: O&M DRAWING SECTION IS PIONEERIN DEVELOPMENT OF DRAWINGS IN AUTO CAD.MANPOWER: TWO DRAFTMENTRAINED IN AUTO-CAD
PRINT ROOM: O&M PRINT ROOM COPE UP THE DAY TODAY REQUIREMENT OF
PHOTCOPYING, CYCLOSTYLLING & AMMONIA PRINTINGOF DRAWINGS REQUIRED FOR INDENTING PURPOSES.MANPOWER: ONE ATTENDANT
DISPLAY ROOM: O&M DISPLAY ROOM LOCATED ATSERVICE BUILDING O MR IS BEING MAINTAINED AND
UPDATED REGULARLY
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NTPC/VINDHYACHAL LONG TERM PLANNINGCONSTRAINTS
UNIT OVERHAUL REPORTS: INSPITEOF ALL BEST POSSIBLEEFFORTS, PROBLEM IS BEING FACED TO GET THE FEEDBACKFROM OTHER DEPARTMENTS FOR THE JOBS COMPLETED,MEASUREMENTS TAKEN AND EXPENDITURE INCURRED
DURING UNIT OVERHAULS, WHICHCAUSES DELAY INCOMPILATION OF UNIT OVERHAUL REPORTS.
OVERHAUL COST: PRESENTLY IT IS DIFFICULT TO GET THEFINANCIAL DATA i. e. UNIT OVERHAULS COST (THE
EXPENDITURE INCURRED DURING RESPECTIVE UNITOVERHAULS). CONTINUOUSLY THESE DATA ARE BEINGASKED BY CC & WR.
ISSUE OF MATERIALS: MATERIALS PROCURRED FOR UNITOVERHAULS MUST BE TAGGED BY STORES AND NOT TO BE
ISSUED TO ANY OTHER DEPARTMENT WITHOUT CONSENT.
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THANK YOU