u#2 oh report 2003

Unit # 2 Overhauling Report

1.0 INTRODUCTION

Unit # II was shut down at 13:27 hrs on 03/03/2003 for Unit # 2

overhaul for 36 days upto 08/03/2003. The Recommissioning activities

were coordinated from the operation Deptt. by the following

Recommissioning team, under the direct supervision of Sri T. K.

Chaudhuri, Sr. Supdt. (Oprn) and overall guidance of Sri G. Vijayakumar,

DGM (O&C) & Sri D. Sarkar, DGM (O-I).

The Recommissioning Team :

01. Sh. A. Mukherjee, Supdt. (O), Team Leader

02. Sh. P. R. Jena, Supdt. (O)

03. Sh. A. K. Paswan, Dy.Supdt. (O)

04. Sh. R. N. Behera, Sr. Engr. (O)

05. Sh. Rahul Kashyap, Engr. (O)

06. Sh. S. R. Sahana, Controller (O)

07. Sh. R. R. Nayak, Controller (O)

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The following are the broad activities, coordinated/carried out by the

Recommissioning Team.

Issue of PTWs on various equipments/auxiliaries/systems after safe

isolation of the same.

Isolation of various HT/LT switchgears.

Inspection of various areas of Boiler & Turbine and generating detailed

defect reports.

Carrying out different tests in coordination with Maintenance deptt.

Waling as a link between the activities of different maintenance units

during overhauling process.

Monitoring & following up of daily progress of overhauling activities

with Maintenance departments for timely completion of overhauling

activities.

Normalization of equipments after cancellation of PTWs and proper

clearance from the concerned departments.

No load/load trial run of equipments are taken.

Checking of Protection & Interlocks for unit & unit Auxiliaries.

Synchronisation of the unit after safety valve floating & electrical

testing.

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2.0 MAJOR JOBS TAKEN UP DURING THE OVERHAUL :

TURBINE SIDE

Condenser HP jet cleaning.

Condenser water box cleaning & Inspection of both Inlet Butterfly

valves.

D/A cleaning/Inspection/ and Repair work.

TDBFP A/B exhaust valve, Gear Box Inspection & Repair.

TDBFP A/B Mechanical seal Inspection & Repair.

CEP # A Motor Replacement.

Recommissioning of various MOVs/POVs.

Overhaul of various HT/LT Swgrs.

Generation Aux. panel maintenance.

GT R/Y/B & UT – A/B PM jobs.

GCB Testing.

P&I Checks.

Gen./Turbine.

BFP A/B/C, CEP-A / B / C, DMCW Pump – A/B/C

HP bypass valves & OSU.

EHC characteristic checks of HP/IP control valves.

EHC characteristic checks of CVs of TDBFP # A & B.

EHC characteristic of LPBP u/s.

HPH 5A/5B / 6A/6B panting plane leakages attended.

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BOILER SIDE

HFO/LDO passing checking was done through corner valves.

APH water washing.

A/B/C/D/E Mills overhauling.

Furnace internal water washing.

ESP transformer boards annual maintenance work done.

Alll ESP passes annual maintenance work done.

All APHs seal Inspection of defective basket replacement.

All LRSBs / servicing done.

Flue gas duct Inspection from APH to ESP & ID fan to Chimney done.

OFFSITES :

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3.0 ISOLATION & ISSUE OF PTWS

All PTWs as per PTW plan and utmost care was taken to ensure human & equipment safety through locking of Breakers/Modules use of lock out boxes for all HT equipments and next of the LT equipments. It was ensured that Mechanical Isolations are proper and fault free.

Separate PTW Books for each Maintenance deptt.

(BMD/EMD/TMD/C&I etc.) were used.

PTW Registers were used area wise (i.e. Boiler/ Turbine/Generator/ Elecrical systems) and entries in the registers were made equipment wise. Separate SFTs were also issued in trial operation against pending PTW cases.

The total no. of PTWs issued during the overhaul are as mentioned

below.

Department No. of PTWs Issued

BMD

EMD

TMD

C&I

4.0 OVERHAUL OF HT/LT SWGRS :

Overhauling of 40 HT/LT swgrs, 12 HT/LT Xfors, 8 HT Motors, 40 LT motors were taken up. This invoked amount of planning & coordination an the part of Recommissioning team.

Load trial run of D4 set – 2 for 5 hr & DG set # 3 for 2 hrs was done to facilitate overhaul of USS # 4 & EMCC tie Breaker respectively. DG set was loaded upto 255 amps / 410 volts.

Hot changeover of EMCC supply was successfully camed out through synchronisation.

5.0 PROTECTION & INTERLOCK CHECKING

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Details checks of various protection & interlocks camed out for Boiler, Turbine and generator. Also P&Is camed out for fly ash handling system and CW system. As per as possible checks were been carried out in actual conditions rather than simulations. The details of P&I checks and protocols are closed in Annexure.

6.0 CHANCE FOR LOAD/NO LOAD TRIAL RUN OF EQUIPMENTS/ NORMALISATION OF SYSTEM :-

This time printed formats of unit Recommissioning procedures have been followed extensively. All the clearances for various drives and of various departments have been brought under same annexure which helped while load/No load trial run and final clearances were given. Even all the vibration readings of equipments recommissioned have been put under identical formats which have been made in a book structure for further safe keeping.

7.0 INSPECTIONS

Extensive Inspection carried out before repair work of various parts of Boiler and Turbine auxiliaries. Flue ducts, exhaust valves, Dead Bus checking were carried out and problems identified. After problem attending again extensive inspections made to check that the defects have been fully liquidated. Jail's protocols have been signed and enclosed in the annexures.

TURBINE SIDE

TDBFP A/B exhaust butterfly valves seals inspection.

Hot well inspection.

FST / Deaerator inspection.

Under CW in/out water box inspection before and after tube cleaning. Lot of dirt / foreign material/ ball found.

AA – AN valves checked for passing. No passing observed during Boiler hydrotest.

CW in/out butterfly valves internal inspection. Valves checked for full closure/passing & found OK.

PAH separator checked and found OK.

Visual Inspection of last stage blades of LP turbine. No damage / abnormality observed.

BOILER SIDE

Inspection of flue gas ducts for Boiler to ID fan discharge including chimney inlet duct, heavy of duct and puncture of several places observed. Attended.

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Inspection of SADC system before overhauling and after attending the defects. Mismatch between load/Remote pressure feed backs observed and attended. Also SADCs which were damaged were attended.

Inspection of Burners of all corners carried out. Burners at various places were damaged and were replaced.

Burner tilt Mechanism checked from local and remote and play adjusted.

Inspection of all ESP hoppers/boiler hoppers for cleanliness.

Inspection of Boiler Ash hopper internals. May places refractories was seen damaged. Refractories of both hoppers were changed.

All Mill purge and dampes/CADS/were checked. Clarifier Inspections were done. Through MillPA ducts and Bypass ducts were inspected and problems of and welding failure identified and defects got attended.

Mill CO2 & fire fighting system checked.

Mill # D lub oil tank inspection was carried out. Total oil of Tank was changed. Fresh oil was put in the Tank. This was done as before O/H. Mill # D lub oil filters were frequently getting choked.

Inspection of ECW Bypass dampers done. Damper full close checked, for both left/right sides.

Dry run of LRSBs & WBs done and checked with both BMD/EMD.

8.0 RECOMMISSIONING OF MOVS /MODS/POVS/PODS :

The following is the list of MOVs / MODs / POVs /PODs

recommissioned during the overhaul

BOILER SIDE

DESCRIPTION VALVE NO. DESCRIPTION VALVE NO.SB Stm Main MOV UV 001 A ECO Vent UV 603 A/BSB MOV Bypass UV 001B ECO Vent UV 604 A/B

HTSH Spray MOV UV 114 B ESP O/L Gates UV 8016 A/B/C/D

HTSH Spray MOV UV 115 B ESP O/L Gates UV 8026 A/B/C/D

HTSH Spray MOV UV 119 B ESP I/L Gates UV 8015 C/DHTSH Spray MOV UV 115 A ECO Bypass UV 8011 A/BITSH Spray MOV UV 115 E ECO Bypass UV 8011 A/BITSH Spray MOV UV 118 E ECO Bypass UV 802 1A/BMS Stop valve (L) UV 102 B SAPH – B FG I/L UV 8013

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Bypass valve- 1MS stop valve (L)Bypass valve – 2

UV 102 C SAPH – A FG I/L UV 8023

IBV (RHS MSV) UV 101 B PAPH – A Air O/L UV 7625IBV (RHS MSV) UV 101 C PAPH – B Air O/L UV 7615

HRH Vent valve - 1

UV 201 A PA Fan – B disch. damper

UV 7613

HRH Vent valve – 2

UV 201 B PA fan – A disch. damper

UV 7623

Drain bef. ITSH UV 1001 A FD Fan –B disch damper

UV 7713

Drain bef. ITSH UV 1001 B FD Fan – B disch. damper

UV 7713

Drain bef. ITSH UV 1001 B FD Fan – A disch. damper

UV 7723

Drain bef. MSV (R) UV 1003 A MS ERV WSE – 12/13Drain bef. MSV (L) UV 1004 A MS ERV WSE – 14/15

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TURBINE SIDE

DESCRIPTION VALVE NO. DESCRIPTION VALVE NO. MS drains MS – 15/16 LPBP drain valve MAN 12AA 212MS drains MS – 18/19 LPBP drain valve MAN 11AA 211MS drains MS – 20/21 HP bypass drain HPBP – 13/14Combined drain after stop valve bef. control valve

MAL 11 AA 211 HP bypass drain HPBP – 17/19

MS hdr drain before strainer

LBA 20 AA 211 HP seat drain MV 104 A

CRH to D/A drain before control valve

LBG 10 AA 211 HPH – 5A alt drip isolation valve

HDH – 14

Drain bef. Gland seal stm blk valve

LBG 10 AA 213 HRH hdr main drain valve

HR-13

Combined main drain bef. CRH isolation valve

LBR 20 AA 211 Aux. Steam to D/A PCV Bypass valve

ASL – 24

TDBFP – 1A Aux. Steam isolation valve.

ASL - 31

9.0 Modifications carried out

TG Side

Low load control valve cage replaced.

Control fluid and also discharge the hangers put to arrest vibration.

Boiler Side

Purification of filter c/o handle of HCOP filter of ID fan both A/B so that filter can be charged over smoothly.

Extension of SAPH # A/B several tube to ensure full steam coverage of the baskets.

10.0 Tests carried out

Sl. No.

Description Date Remarks

1. Main Turbine over speed test 03/03/2003Elec. O/S : Mech. O/S :

2. TDBFP # A actual over speed 06/03/2003 Elec. O/S : of 59


test Mech. O/S :

3.TDBFP # B actual over speed test

06/03/2003Elec. O/S : Mech. O/S :

4. Condenser flood test 08/03/2003Hot well filled upto 6.5 Mt. Elevation

5. Load run of DG set 2 6. Load run of DG set 2

7.Boiler hydraulic test (Internal – 1)

31/03/2003Pressurised upto 216 ksc

8.Boiler hydraulic test (Internal)


9.Boiler hydraulic test (Internal 2)


10.Boiler hydraulic test (Internal 3)


11.Boiler pressurisation Air leak test

07/04/2003

ID fan # A / FD Fan # A kept i/s. Furnace pressurised upto + 45 mm wc.

12.ATT for main turbine safety devices

07/04/2003All devices and checked

13. Gen Electrical Testing 07/04/2003Tests conducted at 3000 rpm.

14. Boiler safety valve floating 07/04/20033 RH safety valves & 8 MS safety valves.

15. TDBFP # A oil injection test 07/04/2003

16. TDBFP # B oil injection test. 07/04/2003

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11.0 SEQUENCE OF ACTIVITIES

03/03/2003 Unit S/D taken for Annual O/H and at 13:27 Hrs unit was desynchronized.

Turbine Actual over speed test done (Both chanels checked)

HFO/LDO passing of corner valves checked. APHs water washing started

04/03/2003 Turbine side HPCVs EHC characteristics checking started.

ABCDE mills PTWs issued to BMD for O/H. Station service swgr Sec. # A & B O/H being done by

EHD. Boiler external water washing started. DMCW/CLCW C/O from Unit # 2 to Unit # 1 for Air

compressors. TMD is decoupling the turbine for speed test. Furnace internal water washing started. All APHs water washing completed. APHs drying started.

05/03/2003 SB PTW issued to EMD. Coal Mill MCC Sec. # A & B PTW issued to

EMD/cancelled/normalised. ESP Xformer & Boards PTWs issued to EMD after hand

tripping. Boiler Internal / External water washing completed. HP/IP EHC characteristic checks completed. LPBP CV EHC characteristic check is in progress. Both ID # A/B Turbine decoupled by TMD for over

speed test. SSS Sec. # A/B O/H completed. Sections normalised. PTW issued on CLCW P/P # 2A for pump inspection. Start up to SB I/C charged. PTW on MDBFP # C for suction strainer replacement &

Booster pump coupling inspection. EHC characteristics of LPBP completed. Control fluid pump discharge header hoppers being

reinforced by TMD. O/H of valves MS-15, 17, 18, 19, 20 HR-13, HPBP 13,

14, 17, 19. APHs drying coupled. APHs PTW issued.

06/03/2003 TDBFP # A/B overspeed test carried out. D/A over flowed and hi & hi hi switches checked. Boiler MCC/Boiler ACDB Annual O/H done. SADC jointly checked with C&I / BMD.

07/03/2003 USS section # B PTW issued. UB Bus PTW issued.

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SAPH A/B, PAPH A/B APH Baskets removed. Scaffolding of Boiler is in progress. CEP # A PTW issued (Both TMD/EMD). Mill A/B/C Main PA/Bypass PA duct inspection

completed. Condenser water box draining started. All APHs GB maintenance work is in progress. PTW issued to TMD on TD # A/B for Inspection/Repair. USS Xfor # B PTW cancelled. PTW on CRH to APRDs main iso. valve and Bypass iso.

valve for valve servicing. 08/03/2003 H2 purging out with CO2 started. (22 cylinders CO2

consumed) Then CO2 purge at with air started. Condenser flood test carried out. 2 UB Bus PTW, cancelled. Normalised. USS Sec # B charged. Flue gas duct APH to ESP Internal Inspection done.

09/03/2003 Hotwell draining started. Hi Hi and hi alarm resetting checked with C&I. PTW issued to TMD for CEP # 2A after P/cable

disconnection. PTW issued to CLCW # 2B for strainer cleaning / NRV

servicing. PTW issued to CEP # 2B for strainer cleaning.

10/03/2003 Chemistry sample of O2 in CO2 taken. CO2 purge at continuing.

BDDC W/PTW. EMCC PTW issued. PTW issued on + 24 V charger # 2 for Annual

maintenance. PTW issued ID Fan # 2A for Motor PM works. Hot well is drained condition. PTW issued on HPH # 5A/5B/6A/6B for attending

panting plane leakages. DMCW # 2B pump decoupled done & NRV being

serviced. Station water level Xmitter cleaning done. Both Risers of CT # 2A/2B opened at CT end and Duct

draining started. Turbine Barring stopped. EMCC PTW cancelled charged. Seal oil system shopped.

11/03/2003 Duct draining is in progress. DNCW Pump # A motor no load trial run taken

vibration readings OK. PTW issued a TVDC & TMCC. PTW a TMCC cancelled, Stator water pump alignment being done by TMD.

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TDBFP # A/B work being done by TMD. 12/03/2003 2UA PTW issued.

Duct draining is in progress. DCSV distribution Board PTW issued. ESP # A pss water washing done. FAHP # 2A no load trial run completed. Mill # A/B PTW issued to EMD a main motor. Duct drained.

13/03/2003 PTW issued a USSS Sec. # A and B/C also. 2UA PTW is pending. Mill classifier inspection done. CW I/L & O/L butterfly valve operation checked. Secondly air duct inspection done. CLCW # 2A/2C – Alignment is in progress. DMCW # 2A/2B – Alignment completed. 2A D/couple

trial run taken. TG Brg. # 6 – Oil leakage attended. LBF # 30 – Jet cage replacement is in progress.

14/03/2003 2 UA PTW cancelled. 2UA Bus charged. 2 UAA 3.3 KV section # A (AC section) O/H done.

Charged. 20 AA 3.3 KV section # B (BC section) PTW issued. Section ACDB PTW cancelled. Normalised. CT Xfor # A DM Xfor # B / FOPH Xfor # B PTW

cancelled. C&I drained. Stator water tank make up taken. Mill #2A / SAP # B no load trial run taken. Water box cleaning by HP Jet started. PRAPH A/B FG I/L duct inspected. SRAPH A/B FG I/L duct inspected. MDBFP # C Rapid start up device commissioned.

Jointly cleaned with C&I.15/03/2003 ESP Pass # A checking done.

2UA all down stream Xfors except CT 2A, UST # A, USB # A are charged.

UAA Sec # B PTW pending. CST inspection done.

16/03/2003 TD # 2A charged from water side for alignment work by TMD.

Stator water flow to alarm checked. TDBFP # 2A FW line charged & Booster pump filled up.

17/03/2003 ANB oil pump pressure setting is being done. AA/AN oil pump pressure setting is being done. DMW Pump # 2B D/couple no load motor trial run

taken. PTW issued for Turbine area CVs for cleaning &

calibration to C&I. 2UA & 2UB Bus charged from 5A & 5B respectively

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through start up and UT # 2A/2B incomer was made off & Breaker racked out.

PTW issued to EMD on Annual O/H of GT # 2 & UT # 2A/2B.

PTW issued an excitation system for O/H. CW water box (RHS) jet cleaning is in progress. ESP A pass rapping motors RW and Internal Inspection

done with BMD/EMD. 18/03/2003 Hot well Inspection done.

MDBFP # C Interlocks & Protections checking completed.

PTW issued on UPS to C&I. Tube cleaning (LHS) is in progress. D/A to condenser control valve is having passing. TMD

is attending. ANB & HPBP oil pumps protections & interlocks

checked. Both SAPH Basket cleaning going on. Sector plates

being checked. Both PAPH sector plates checked. Mills O/L duct checked. Both Bypass & through Mill. DMCW Pump # B coupling done after no load trial run. CEP # 2A/2B/2C strainers cleaned by TMD. CT 2A/2B both Basins inspected. PTW issued to TMD on AOP 1 & 2, CEP 1 & 2.

20/03/2003 Mill # A & E lub oil system Protections & Interlocks checked.

DMCW Pump # A & B Protections & Interlocks checked. DMCW Pump # C No load trial run taken. DMCW Pump # A & B load trial run taken. TDBFP # A exhaust valve checked. A/C MCC PTW issued. A/C MCC PTW cancelled. PTW issued to TMD for valve modification of condenser

water line & chiller water line. 21/03/2003 TDBFP # B exhaust valve checking done.

CST 2B filled up. All equalising valves lined up. Normalised.

TACDB PTW issued. Fly ash MCC section # A PTW issued to TMD. TP # 5 BC not closing problem attended by EMD. A/C valve modification done. PTW cancelled. FD Fan # A/B, PA Fan A/B P&I checks done. Load trial run of DMCW pump 2A/2B taken. Vibration

readings taken. Hot well filling started. Lo Lo & Lo alarm reset values noted. Mill # D lub oil P&I checked. Generator relays checked by EMD jointly with

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commissioning. Control fluid pump no load trial run taken. 3.3 KV fly ash sec # A PTW cancelled. Charged.

22/03/2003 CEP # B/C P&I checked. PTW issued on CEP B&C for electrical lug replacement. Stator water Regeneration unit Resin Replacement

done by TMD and kept under flushing for 8 hrs. PTW issued on Ex 5-19, HAL 11 AA 213,LBR 10AA 212,

LBC 11AA 211, CO-86 for valve servicing. Gen. Aux. panel PTW issued. Cancelled. Normalised. Mill # A & E feeders trial run taken for 8 hrs. Then

stopped. 23/03/2003 Mill # B lub oil P&I checks completed.

FD Fan A/B, PA fan A/B, CEP # 2C, Mill # 2C PTW issued to EMD.

US section # A I/C Breaker not closing problem attended by EMD.

ESP # B Internal Inspection done with BMD.

24/03/2003 PTW issued an Air ventilation MCC to EMD. Cancelled. Normalised.

PTW issued an TP # 8 to EMD. PTW issued a Ash Extraction Xfmer # A & B to EMD. TG AOP # 1 & 2 No trial run taken. Mill # 2A No load trial run taken. TDBFP # A oil system taken i/s. PTW issued on Boiler ACDB Sec # A to EMD for MCC

O/H. Cancelled. Normalised. USS Sec # A charged. Section kept individually

charged. ID Fan # A & B P&I checks done. Both condenser passes tube cleaning completed. ESP # C pass Internal Inspection jointly done with

BMD. SRAPH A/B FG I/L dampers operation charged. Corner # 2 clearance given by BMD for putting

Ignitors/Scanners.25/03/2003 TP # 8 under PTW. PTW cancelled. Normalised.

Mill # 2B no load motor trial run taken. CEP # 2A No load motor trial run taken. DMCW # A Decoupled to check vibration problem. Low load control valve being checked by TMD. Mills B/C/D feeder O/L gates actuators replaced. Values UV 1001A, B, 1002 A,B 1003 A, B 1004 A, B

actuators serviced. CW O/L scanners of LHS/RHS done. Joint Inspection

also done. Joint checking of CW duct & CW I/L butterfly valve

done.

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FST drained. Joint checked of DA & FST done. All vac. Pumps & FAHP # 2B motor PTW issued for

EMD. MS & RH ERVs checked after BMD clearance.

26/03/2003 Mill # 2C lub oil P&I checks done. Corner # 2 Ignitor/Scanners checked. Mill # 2A/2B Mill Motor coupling done. ESP # D pass Inspection done. FST # D pass Inspection done. Air I/l PRAPH/SRAPH / dampers checked. Operation. Air O/L PRAPH.

27/03/2003 CW duct filling started. DMCW Pump A & B load trial run taken. Mill # A / SAF # B no load trial run taken. Air O/L dampers of all APHs operated at local. D/A, FST repair work in progress. PTW issued a BVDC. Cancelled. Normalised.

28/03/2003 CW Duct filling in progress. DMCW pump # C taken i/s after coupling. DMCW pump # B taken i/s. CLCW pump # A & C taken i/s. Boiler side DMCW charged. ESP I/L & O/L dampers operation checked. All actuators/ valves who permit cancelled operation

checked. FST filled up after repair.

29/03/2003 AOP # 1 & AOP # 2 load run taken. Mill # 2D no load trial run taken. Mill # 2E P&I checks completed. LP Turbine last stage slade Inspection done. TDBFP # A P&I checks completed. CEP # A clearance given for running. CEP # B & C run.

30/03/2003 Mill # A P&I checks completed. Corner 1 & 4 scanners & Ignitors checked. CEP # A taken i/s. MDBFP # C started in R/C for Trial run.

31/03/2003 Boiler filling & flushing done (c lines). Boiler hydrotest (Internal) done at 216 ksc. PAPH # 2A & SAPH # 2A SB & GB lub oil system

clearance given. Lub oil pumps taken i/s. Joint Inspection of APH to ESP and ID to cleaning duct

done. WBs and LRSB trial operation cleaning by BMD/EMD.

01/04/2003 MFT I/l protection checked. Mill # C protection checked. PAPH # A & SAPH # B trial run started. PA fan # A Motor trial run taken. All DC oil pumps vibration & speed Measurement done

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by MTP. Main Turbine I/L protection checked. PTW on AOP # 1 issued to EMD. PA Fan # A/B, FD Fan A/B discharge damper

open/close cleared by local.02/04/2003 SAPH A & B / PAPH A&B Internal Inspection done.

P&I of fail safe protections checked. Aux. TG checked. Found OK. AOP # 1 taken i/s. LPBP protections completed. CO # 86 limit switch adjustment done by EMD. JOP 3.3 high vibration problem attended. Boiler hydrotest (External) for Boiler Regulating

Authenties permit raised upto 215 ksc. 03/04/2003 Cold end soot blowers operated with BMD.

TDBFP # B oil system taken i/s. TDBFP # B water charging done. TDBFP # B P&I checks completed. Fly ash system (P&I) checks done. Mill CO2 system checked for all mills with C&I/BMD. Turbine put a barring. AN value seat adjustment done.

04/04/2003 Generator mechanical P&I checks done. Generator electrical P&I checks done. TDBFP # B P&I checks completed. Corner # 3 scanners/ignitors checked. AA/AN/ANB valve operation checked. Speed switches put an all APHs by C&I. TD # B put on BG. Control fluid pump # 2A load trial run taken. CLCW pump # 2b / JOP 3.3 taken i/s.

05/04/2003 CW Pump # 5 started. PTW on excitation system cancelled. UT # 2A/2B emulsifier checked. Mill # 2C motor no load trial run taken. AC scanner air for started. Flushing done.

06/04/2003 Boiler Hydrotest – III (Internal) done at 140 ksc. APRDS charged. RH leakage test doe by Vac. Putting. Seal trough filling done. CW Pump # 4 started. H2 filling started. 27 CO2 cylinders consumed. 132 H2 cylinders consumed.

07/04/2003 Boiler lighted up. Air pressuriszation test done. Hot draining done. Safety valve floating done.

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ANNEXURES

(I TO V)

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UNIT # 2 OVERHAUL

ANNEXURE – I

The following is the list of SWGRs (HT/LT) overhauled during the overhaul.

a) HT SWGR (11 KV) :

Sl. No.

DescriptionDate of Isolation

Date of Normalisatio

n1. 1 UB2. SA

b) HT SWGR (3.3 KV)

Sl. No.



n1. 1 UAA (SEC – A)2. 1 UAA (SEC – C)3. 1 UAA (SEC – B)4. FLY ASH MCC(SEC – B)

c) LT SWGR (415 V)

Sl. No.



n1. SSS – A2. SSS – B3. USS – A4. USS – B5. TMCC – A6. TMCC – B7. BMCC – A8. BMCC – B9. COAL MILL MCC – A10. COAL MILL MCC - B

Sl. No.



n

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11. STATION ACDB – A12. STATION ACDB – B13. TURBINE ACDB – A14. TURBINE ACDB – B15. BOILER ACDB – A16. BOILER ACDB – B 17. ESP BOARD – C SEC – 118. ESP BOARD – C SEC – 219. ESP BOARD – D SEC – 120. ESP BOARD – D SEC – 221. ESP BOARD – A SEC – 122. ESP BOARD – A SEC – 223. ESP BOARD – B SEC – 124. ESP BOARD – B SEC – 225. EMCC26. TVDC27. BVDC28. BDDC29. SOOT BLOWER MCC30. ASH EXTRACTION MCC SEC – A31. ASH EXTRACTION MCC SEC – B32. CT MCC – A33. UCR A/C MCC

d) MISCELLANEOUS :

Sl. No.



n1. 220 V CHARGER – 12. 220 V CHARGER - 23. + 24 V ABB CHARGER – 1& 24. UPS BATTERY SET (CAPACITY

TEST)

Sl. No.



n5. UPS BATTERY SET

(REPLACEMENT OF BYPASS CELLS)

6. 24 V/48 C/100 V CHARGER –1)7. 24 V / 48 V / 100 V CHARGER –

28. GEN AUX. PANEL 9. CSSAEP 10. MAIN TG DC STARTER PANEL

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e) HT/LT TRANSFORMERS :

Sl. No.



n1. GT # 1 (R/Y/B)2. GT # 1 (R/Y/B) MB & Common

Kiosk 3. CW SERV. XMER – A4. ESP XMER – 1A5. FOPH SERV XMER – A6. ASH EXTRACTION MXER – A

(TP – 5)7. ASH EXTRACTION XMER-B

(TP-8)8. UNIT SERVICE XMER – 1B (for

painting)9. UNIT SERVICE XMER – 1A (for

painting)10. STN SERVICE XMER –1B (for

painting)11. STN SERVICE XMER – 1A (for

painting)

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UNIT # 2 OVERHAUL

ANNEXURE – II

The following P&I checks were carried out during the overhaul (Details given under Protoclos) A) BOILER & AUXILIARIES :

SL. NO.

DESCRIPTION DURATION

1.

MAIN BOILER P&I Purge permissive MFT Conditions Boiler alarms LDO – HFO System Fail Safe Checking

2. ID FANS – A/B

3. FD FANS – A/B

4. PA FANS – A/B

5. MILL – A LUB OIL SYSTEM

6. MILL – B LUB OIL SYSTEM

7. MILL – C LUB OIL SYSTEM

8. MILL – D LUB OIL SYSTEM

9. MILL – E LUB OIL SYSTEM

10. MILL – A MAIN MOTOR PROTECTIONS

11. MILL – B MAIN MOTOR PROTECTIONS

12. MILL – C MAIN MOTOR PROTECTIONS

13. MILL – D MAIN MOTOR PROTECTIONS

14. MILL – E MAIN MOTOR PROTECTIONS

15. OSU OF AA – AN V/Vs

16. OSU OF ANB V/V

17. BOTTOM ASHING SYSTEM

18. FLY ASHING SYSTEM

B) TG & AUXILIARIES :

SL. NO.


1. MAIN TURBINE PROTECTIONs

2. SGC LUB OIL SYSTEM

3. SGC TURNING GEAR

4. SGC HYDRAULIC FLUID SYSTEM

5. SGC SEAL OIL SYSTEM

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6. SGC STATOR WATER SYSTEM

7. OSU HPBP SYSTEM

8. HPBP V/Vs & SPRAY V/Vs

9. DMCW PUMP - A/B

10. DMCW PUMP – C

11. CEP – A

12. CEP – B/C

13. DMBFP

14. TDBFP – A

15. TDBFP - B

C) ELECTRICAL SYSTEM :

SL. NO.


1. MAIN GENERATOR PROTECTIONS

2. GCB AUXILIARIES

3. GCB INTERLOCKS

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UNIT # 2 OVERHAUL

ANNEXURE – III

BOILER # II SAFETY VALVE SETTINGBY HYDRAULIC PRESS METHOD

Sl. No. Safety Valve No.

Design Press (ksc)

Actual Available

Press (ksc)

Hydroset Oil Press

(ksc)

Actual Lifting

press (ksc)1. WSE 001 215.0 131.5 67 215.0

2. WSE 002 217.0 134.0 67 216.0

3. WSE 003 214.0 135.5 54 214.0

4. WSE 004 212.5 135.0 54 214.0

5. WSE 005 215.5 140.0 60 213.4

6. WSE 006 217.0 140.0 64 218.0

7. WSE 007 201.5 124.0 62 200.5

8. WSE 008 201.5 122.0 65 201.5

Operation BMD Date of TestSignature :Name :Designation

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The following dampers have been operated at local on

26/03/2003.

SRAPH # A FG I/L damper - Operated OK.

SRAPH # B FG I/l damper - Operated OK.

PRAPH Air I/L damper - Operated OK.

SRAPH # A Air I/L damper - Operated OK.

PRAPH # B Air I/L damper - Operated OK.

SRAPH # B Air I/L damper - Operated OK.

PRAPH # A Air O/L damper UV 7625 - Not taking command.Total not closing.

SRAPH # A Air O/L damper UV 7725B - Not taking commandUV 7725 C 70 % doing, then mechanical

jamming.

SRAPH # B Air O/L damper UV 7715B - Not taking commandUV 7715 C 60 % closing, jamming.

PRAPH # b Air O/L damper UV 7615 - Closing but remaining around 5 %

Open.SRAPH # A/B FG I/L dampers bottom seal in damaged condition and flap to flap seal not present.

Checked By Sign. :Name : Desig. :Deptt. : Operation

Checked By Sign. :Name : Desig. :Deptt. : B M D

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RECORD OF FST/DEAERATOR CHECKING

Checked on 25/03/2003 along with TMD personnel.

FST PROBLEMS

TDBFP # A suction inlet net in FST has hot displaced.

TDBFP # B suction inlet net and parting plate has got displaced.

Parting plate has to be rewelded.

MDBFP # C parting plate of suction line welding is in cracked condition.

Parting plate has to be rewelded.

DEAERATOR PROBLEMS

01 no. of nozzle bolt is in loose condition.

Aerator plates has got displaced from it's original position.


Checked By Sign. :Name : Desig. :Deptt. : T M D

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INSPECTION REPORT OF 'C' PASS OF ESP

Following numbers of plates were not having adequate distance

between emitting and collecting plate.

01. 1C2 - 03 Nos.

02. 2C2 - 04 Nos.

03. 3C2 - 02 Nos.

04. 3C1 - 01 No.

05. 4C2 - 02 Nos.

06. 5C2 - 03 Nos.

07. 5 CL - 02 Nos.

08. 6C2 - 02 Nos.

09. 7C2 - 01 No.

The following number of plates were not having free movement.

01. 2C2 - 01 Plate

02. 5C1 - 01 Plate

03. 7C1 - 01 Place

The above problems were shown to AHD.


Checked By Sign. :Name : Desig. :Deptt. : A H D

RECORD OF CHECKING OF CW DUCT (BOTH LHS/RHS)

LHS CW duct inlet inspected on 25/03/2003.

Mud, Leaves, Taprogee balls, Wooden blocks found in the CW duct inlet

portion.

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CW I/L butterfly valve LHS operation checked. Opened & closed.

Found OK.

RHS CW duct inlet inspected on 26/03/2003.

Mud, leaves, taprogge balls, Wooden blocks found in the CW duct inlet

portion.

CW I/l butterfly valve RHS operation checked. Opened & closed. Found

OK.

I/L Butterfly valve seal is damaged in four nos. places.



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INSPECTION REPORT OF 'D' PASS OF ESP

Following plates (nos.) were found to have inadequate distance

between them.

01. 2D1 - 02 Nos.

02. 2D2 - 02 Nos.

03. 6D1 - 03 Nos.

04. 6D2 - 03 Nos.

05. 7D1 - 07 Nos.

06. 7D2 - 01 Nos.

07. 5D1 - 03 Nos.

08. 5D2 - 03 Nos.

09. 3D2 - 10 Nos.

10. 3D2 - 04 Nos.

02 plates in pass 1D1 were found to have loose clamps.

01 plate in pass 3D1 was not having free movement.

In following passes hammers were found to strike the flame before

hitting the shock pad.

01. 1D1 - 01 hammer

02. 1D2 - 01 hammer

03. 5D1 - 01 hammer

04. 6D1 - 01 hammer



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INSPECTION REPORT OF 'B' PASS ESP

Following numbers of plates were found to have more gap as compared

to allowable limit.

01. Pass no. – 2B1 - 01 plate

02. Pass no. – 3B1 (NDE) - 01 plate

03. Pass no. – 4B2 - 01 plate

04. Pass no. 5B1 - 03 plates (problems was attended)

05. Pass no. – 7B2 - 02 plates

Pass no. 4B1 – 02 plates were not having free movement. '

Pass no. 1B1 – 01 plate was not having free movement.

Above problems were shown to A.H.D.



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DEFECTS / PENDING

Corner – 1

Level – 2 Oil both flaps in Operative (K) (BMD work line to be put).

Corner – 3

Level – 2 oil damper lower flap not operating (K) (BMD work) Line to be

put.

Level – 2 lower aux. air damper not operating fully (J) (80 % open)

Corner – 4

Level – 1 oil damper mech. – Jamming (N)

Level – 2 oil damper lower flap inoperative (K)



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TDBFP # A EXHAUST VALVE INSPECTION DATE: 20/03/2003

Seat of the valve was slightly roughed up.

Water present inside the duct.

Valve was closed manually and valve seat checked.

TDBFP # B EXHAUST VALVE INSPECTION DATE: 21/03/2003

Valve seal damaged in 02 nos. places.

Water present inside the duct.

Valve was closed manually and valve seat checked.



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PROBLEMS IDENTIFIED DURING INSPECTION OF ESP – A PASS

Date : 15/03/2003

A) Problems found during inspection of gap between emitting

and collecting electrodes.

The gap between electrodes were either more or less and this was

shown to BMD.

Pass 1A1 – 03 Nos.

Pass 4A2 – 10 Nos.

Pass 5A2 - 04 Nos.

Pass 3A2 - 04 Nos.

Pass 6A2 - 05 Nos.

Rapping motor shaft at some places were also eroded and same

was shown to BMD.

B. Problems identified when rapping motors were taken I/S.

2A2 - One of the hammers of C.E. was striking the beam before

striking the striker plate thereby leading to loss of momentum. This was

shown to BMD.

6A2 - Same of the hammers were offset from their position. This was shown to BMD.



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INSPECTION OF C.S.T. – B IN DRAINED CONDITION

Date : 15th March'2003

Checkings done :-

01. Epoxy painting found intact.

02. C.S.T. is fully cleaned and no debris were found.

03. Mechanical float was inoperative. T.M.D. replaced the tape and now is in working condition.

04. TMD was informed for box up.



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UNIT # 1 UNIT # 2

CST B

Drain

RecirculationCST A

Drain

U # 1U # 2

U # 1 sideU # 2 side closed

closed

spill

From DM

CT 2 CT 1


INSPECTION OF MILLS A, B, C MAIN PA & BYPASS PA DAMPERS

Main PA/Bypass PA damper seal eroded of Mills ABC.

Main PA welding joint after main PA dampers damaged Mills ABC.

Mill # A DE Bypass duct first expansion joint before bypass PA damper

disturbed.

Mills C/D/E main PA duct welding hole in left side wall.

Mill B / NDe side bypass PA screen to mixing chamber welding

damaged.

Mill # A / DE & NDE side bypass PA screen to mixing chamber welding

damaged.

Mill # B DE side bypass PA duct after damper welding change.



SADC CHECKING Date : 06/03/2003Corner - 2 Corner - 3

LVL-1A

0 - OK O LVL-1 A 0 - OK O50 - OK 50 - OK

100 - OK 100 - OKC 0 - OK C 0 - OK

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50 - OK 50 - OK100 - OK 100 - OK

O0 - OK

N O0 – 10 % open

N50 - OK 50 - OK100 - OK 100 - OK

C0 - OK

M

C0 - OK

M

50 - OK 50 - OK100 - OK 100 - OK

A0 - OK

A0 - OK

50 - OK 50 - OK100 - OK 100 - OK

LVL-2A

0 - OK

L

LVL-2

A 0 - OK

L

50 - OK 50 - OK100 - OK 100 - OK

C0 - OK

C0 - OK

50 - OK 50 - OK100 - OK 100 - OK

O0-10% open

K O0 – upper flap lower flap

K50 - OK 50 - OK100 - OK 100 - OK

C0 - OK

J

C0 - OK

J

50 - OK 50 - OK100 - OK 100 - OK

A

0 - OK

A

0 - OK50 - OK 50 - OK

100 - OK 100 – 80 % opening

LVL-3A

0 - OK

I

LVL-3

A0 - OK

I

50 - OK 50 - OK100–80 % opening 100 - OK

C0 - OK

C0 - OK

50 - OK 50 - OK100 - OK 100 - OK

O0 - OK

H O0 - OK

H50 - OK 50 - OK100 - OK 100 - OK

C0 - OK

G

C0 - OK

G

50 - OK 50 - OK100 - OK 100 - OK

A0 - OK

A0 - OK

50 - OK 50 - OK100 - OK 100 - OK



Checked By Sign. :Name : Desig. :Deptt. : C&I

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SADC CHECKING Date : 06/03/2003Corner - 2 Corner - 3

LVL-4A

0 - OK

F

LVL-4

A 0 - OK

F

50 - OK 50 - OK100 - OK 100 - OK

C0 - OK

C0 - OK

50 - OK 50 - OK100 - OK 100 - OK

O0 - OK

E O0 – 10 % open

E50 - OK 50 - OK100 - OK 100 - OK

C0 - OK

D

C0 - OK

D

50 - OK 50 - OK100 - OK 100 - OK

A0 - OK

A0 - OK

50 - OK 50 - OK100 - OK 100 - OK

LVL-5A

0 - OK

C

LVL-5

A 0 - OK

C

50 - OK 50 - OK100 - OK 100 - OK

C0 - OK

C0 - OK

50 - OK 50 - OK100 - OK 100 - OK

O0 - OK

B O0 - OK

B50 - OK 50 - OK100 - OK 100 - OK

C0 - OK

A

C0 - OK

A

50 - OK 50 - OK100 - OK 100 - OK

A0 - OK

A0 - OK

50 - OK 50 - OK100 - OK 100 – OK




SADC CHECKINGCorner - 1 Corner - 4

LVL-1A

0 - OK

O

LVL-1 A 0 - OK

O

50 - OK 50 - OK100 - OK 100 - OK

C0 - OK

C0 - OK

50 - OK 50 - OK100 - OK 100 - OK

O 0 - OK N O 0 – OK NMech. Jam.50 - OK 50 - OK

100 - OK 100 - OK

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Damper plate eroded

Both damper disconnected


C0 - OK

M

C0 - OK

M

50 - OK 50 - OK100 - OK 100 - OK

A0 - OK

A0 - OK

50 - OK 50 - OK100 - OK 100 - OK

LVL-2A

0 - OK

L

LVL-2

A0 - OK

L

50 - OK 50 - OK100 - OK 100 - OK

C0 - OK

C0 - OK

50 - OK 50 - OK100 - OK 100 - OK

O0- OK upper flap lower flap in

operative

KO

0- OK upper flap lower flap in operative

K50 - OK 50 - OK

100 - OK 100 - OK

C0 - OK

J

C0 - OK Upper

portion slightly

corroded

J

50 - OK 50 - OK100 - OK 100 - OK

A0 - OK

A0 - OK

50 - OK 50 - OK100 - OK 100 - OK

LVL-3A

0 - OK

I

LVL-3

A0 - OK

I

50 - OK 50 - OK100 - OK 100–80 % open

C0 - OK

C0 - OK

50 - OK 50 - OK100 - OK 100 - OK

O0 - OK

H O0 – OK (Mech. Jam)

H50 - OK 50 - OK100 - OK 100 - OK

C0 - OK

G

C0 - OK

G

50 - OK 50 - OK100 - OK 100 - OK

A0 - OK

A0 - OK

50 - OK 50 - OK100 - OK 100 - OK




SADC CHECKINGCorner - 1 Corner - 2

LVL-4A

0 - OK

F

LVL-4

A 0 - OK

F

50 - OK 50 - OK100 - OK 100 - OK

C0 - OK

C0 - OK

50 - OK 50 - OK100 - OK 100 - OK

O0 - OK

E O0 - OK

E50 - OK 50 - OK100 - OK 100 - OK

C0 - OK

D

C0 - OK Mech.

Jamming

D50 - OK 50 - OK

100 - OK 100 - OK

A0 - OK

A0 - OK

50 - OK 50 - OK100 - OK 100 - OK

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LVL-5A

0 - OK

C

LVL-5

A 0 - OK

C

50 - OK 50 - OK100 - OK 100 - OK

C0 - OK

C0 - OK

50 - OK 50 - OK100 - OK 100 - OK

O0 - OK Mech.

jamming

BO

0 - OKB50 - OK 50 - OK

100 - OK 100 - OK

C0 - OK

A

C0 – 10 % open

A

50 - OK 50 - OK100 - OK 100 - OK

A0 - OK

A0 – 10 % open

50 - OK 50 - OK100 - OK 100 – OK




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HPT EHC 2MAX 26 AU01 (PRE OVERHAULING)

Command

EHC F/bCoil

CurrentOil Pr.

HPT (Left) HPT (Right)Left Hdr.

1 MAA 11 AA 011

Left Vent1 MAA 11 AA 012

Left Hdr. 1 MAA 12 AA

011

Left Vent1 MAA 12 AA 012

0 % 6.54 4.5 105.7 / 0.55 101.7 / 1.85 107.1/-0.3 % 105.4/1 %10 % 7.71 5.8 4.7/21.7 101.7/1.85 107.1/-0.3 % 94.4/22.6 %20 % 8.89 7.3 9.8/32.30 101.7/1.85 107.1/-0.3 % 89.6/32.2 %30 % 10.15 8.9 85.4/41.4 % - - 85.1/40.9 %40 % 11.32 250 mA 10.5 81.3/49.6 % - - 81.3/48.6 %50 % 12.50 12.0 72.2/58.1 % - - 77.1/57.8 %60 % 13.67 13.6 59.7/100 % 92.6 %/19.8 % 107.1/-0.3 % 61.8/87.3 %70 % 14.94 15.20 55.10/100 % 80.90/43.0 % 107.1/-0.3 % 52.90/99.90 %75 % 15.52 16.00 55.10/100 % 74.80/55.13 % 107.1/-0.3 % 52.90/100 %80 % 16.11 16.90 55.10/100 % 65.60/71.73 % 107.1/-0.3 % 52.90/100 %85 % 16.70 17.60 55.10/100 % 48.70/100 % 92.7/32.3 % 52.90/100 %90 % 17.38 18.50 55.10/100 % 48.70/100 % 80.4/58.1 % 52.90/100 %95 % 17.97 19.40 55.10/100 % 48.70/100 % 66.0/91.1 % 52.90/100 %100 % 18.55 20.20 55.10/100 % 48.70/100 % 57.1/100 % 52.90/100 %105 % 19.14 21.00 57.1/100 %



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IPT EHC 2MAX 28 AU 004 (PRE OVERHAULING)

Command

EHC F/bCoil

CurrentOil Pr.

IPT (Left) IPT (Right)Stroke CER/Fb Stroke CER/Fb

0 % 8.00 4.7 264.2 0.732 263.9 0.3 %10 % 9.08 6.0 230.5 19.97 230.6 19.92 %20 % 10.15 7.4 225.0 23.15 224.9 23.1930 % 11.33 8.8 219.5 26.4 219.3 26.340 % 12.40 10.2 213.7 29.78 213.7 29.5450 % 13.57 11.7 207.3 32.9 198.1 32.760 % 14.65 13.2 203.0 36.0 202.8 35.970 % 15.82 14.7 197.8 39.0 197.4 39.080 % 16.89 16.2 192.2 42.3 191.4 42.790 % 17.97 17.8 179.8 49.7 179.4 53.995 % 18.55 18.5 124.9 83 108.5 93100 % 19.14 19.3 89.7 99.9 91.2 99.9105 % 19.72 20.1 89.7 91.2



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u#2 oh report 2003

Documents

overhauling report unit

maintenance deptt

unit unit auxiliaries

recommissioning activities

dgm o

controller o

maintenance departments

panel maintenance