Life Assesment of Boilers

8/13/2019 Life Assesment of Boilers

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Bharat Heavy Electricals Limited, Tiruchirapalli

e come

Committed to making a better world


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resen a on rrangemen

. n ro uc on

2. Module of a typical RLA Study3. BHEL contribution in the area of RLA4. ni T t F iliti t BHE

5. Current developments in BHEL in the



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LEP

N on-pres su re Part s Pres s ure Part s

RLAPETCondit ion As sessm en t

R&M Pro osal



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RESIDUAL LIFE ASSESSMENT STUDY

s u y con uc e as ca y o n ou :

pressure parts and piping

To determine the remaining left out life of thepressure parts

Enable to take Run, Re air and Re lacement decisionsProvide technically sound and viable input for R&M



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Why RLA Study

pera on o o er a e eva e

temperatures more than design limit Variations in coal quality

ev a ons n a er em s ry



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Why RLA Study

ros on on on e ou er sur ace o e rum ue o

steam leakage



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Why RLA Study

Sagged Header



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Why RLA Study

Foreign Body inside RH Inlet Header



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y u ySeawater Corrosion in S-Panel



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RLA Study Aims At

Evaluation of present condition of pressure

par s p p ng

Avoiding premature pressure parts failuresand associated unforeseen outages

Identification of problem areas

Analysis of root cause of problems

Providing technically sound and viable



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RLA of What?

Pressure parts

Highly varying duty

Varying Load, Cyclic Load

Fuel Quality Variations

Carried out extensively

Structural parts Limited study

Need based

Visual examination gives good clue Non pressure parts

Mostly maintenance oriented


an e assesse eas y


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RLA STUDY

Pre-Site Study Phase Site Study Post-Site Study Phase

Tender Review/

Review of requirements based

on available information

Review of Operational History Laboratory Analysis

-

Replica Evaluation

Discussions with Utility Scheduling of Activities Review & Finalisation

Scope Finalisation Preparatory Works Report Preparation &

o ecommen a ons

Submission of Offer Study & Preliminary proposals for improvement

Submission


Report Submission


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Steam Generating Unit

PRESSURE PARTS

HIGH TEMP (>400 C) HIGH THICKNESSSH HEADERS, DeSH

MS HRH & PRDS PIPINGS

LOW TEMP (


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erv ce ours enera on ecor s a n enance ecor s

o. o ar -ups va a y ep acemen ecor s

Transient Conditions PLF Design Changes

Steady State Conditions

Excursions

Failure History Inspection Records

RLA/CA/PET



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Stages of Residual Life Assessment

Re ie of ast o erational &

maintenance data of the plant including

water chemistry variations

Field testing

Laboratory testing



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Review Of Past Data

Plant operation

Number of start-ups & shut downs

O eratin conditions

Operating practice

a n enance an repa rFailures and repairs

Review of root cause analysis



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sua nspec on

Erosion, corrosionSwelling, scaling

,

Supports, pipe hangers etc

Dimensional checks

ThicknessOutside diameter



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Field Testin

Non destructive examination

Penetrant testing including fluorescent type

Ma netic article ins ection Wetfluorescent & Dry)

Ultrasonic

In-situ hardness checks

Tube sampling - WW internal deposits

WW H2 embr ttlement



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,

Metallography In situ metallographic examination

roscop c nspec on S ot chemical check when needed



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T ical Tests Done for RLA

Hi h tem erature headers & i in

Ultrasonic, dye-penetrant tests

roscopy, rep cas

Other inspections like

Dimensions, Internal inspection

In-situ hardness



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uper ea er e ea er u es

Tube samples, ultrasonic test OD & Thickness

Deposit Analysis

Steam side oxide scale thickness Life prediction

Attemperators

Ultrasonic, dye penetrant tests Replication, hardness

Fibroscopy



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rums owncomers

Ultrasonic d e- enetrant tests

MPI (Wet fluorescent & Dry)

Fibroscopy

Tube samples, ultrasonic testDeposit analysis (Internal & External)



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Visual Inspection

ep ca on, n-s u ar ness

OD & thickness angers uppor s nspec on

Stress analysis to identify the most stressed points

enera gu e nes or se ect ng nspect on po nts High turbulence or velocity zones

on ensa on po n s

Dead ends & high stressed points

points

All su orts


Bh H El l L d h ll


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Tubes samples from high heat flux zone

Detailed dimensional measurements

Presence of internal deposits covering

epos con en

Constituents of deposit

o ven se ec on c ean ng s necessary

Presence of external and internal corrosion

Micro structure analysis (hydrogen damage)


Bh t H El t i l Li it d Ti hi lli


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Microscopy & SEM)

Deposit analysis ( Internal & External)

cce erate creep rupture test ng


Bh t H El t i l Li it d Ti hi lli


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Scope of RLA as per IBR 391 A

Component Visual

Ultrasonic

testing

particel

testing

penetrant

inspection Replication Sampling

Deposit

Analysis

Drum (Steam) Yes Yes No * Yes Yes No Yes

Water Drum Yes Yes No * Yes Yes No Yes

*

Attemperator Header Yes Yes No * Yes Yes No No

High Temp Header Yes No No * No No Yes No

Low temp eco tubes Yes No No * No No Yes No

Convection SH coils Yes No No * No No Yes Yes

Primary SH coils Yes No No * No No Yes No

Prefinal SH coils Yes No No * No No Yes No

Final SH Coils Yes No No * No No Yes No

Reheater coils Yes No No * No No Yes NoHigh temp header Yes Yes No * Yes Yes No No

Final SH header 'Yes Yes No * Yes Yes No No

Reheater Header Yes Yes No * Yes Yes No No

a n s eam p p ng es o o o es o o

Platen SH header Yes Yes No * Yes Yes No No

Primary SH header Yes Yes No * Yes Yes No No

Economizer header Yes No No * Yes No No No

Auxiliaries Yes No No * No No No No

Boiler bank tubes Yes No No * No No No NoWater wall Yes No No * No No Yes No

Furnace water walls Yes No No * No No Yes No

* MPI will be done on case to case basis

** Oxide scale based life prediction will be done based on operational history and failures

*** UT for checkin inte rit of butt welds


$ Header internal inspection by fiberscope

Bharat Heavy Electricals Limited Tiruchirapalli


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Microstructural Evaluation By Replication

Sampling Thick Walled Components Is

Non-destructive Technique Adopted

or va ua on s ep ca on. To examine s heroidisation and

cavitation level




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Re lica Techni ue

The material surface preparation by

grinding, polishing and etching

e p as c se rep ca s app e rm y

to the surface

After curing, the replica can be removed

an go spu ere e opograp ca

image of the micro structure is examined




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o pu ere ep ca



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Cree Cavit Level Classification S stem Pro osed

by Wedel & Neubauer




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y , p

Indian Boiler Re ulationsASME

ANSI

DIN




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y p

Organisation for RLA in BHEL

R&M department Supporting Depts Service After Sales

Scope of Work

Technical ,Report Preparation

FES, WRI

Central LabNDTL

Offer Submission

Order ReceiptReport to Customer &

ar ca on , orp o er nspec ora e




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y p

Supporting Depts

For

NDE TUBE FAILURE ANALYSIS WATER CHEMISTRY &OXIDE SCALE THICKNESS

INSITU METALLOGRAPHY

Specialised Work

NDTL,SAS CENTRAL LAB Corp. R&D

ACCELERATED

CREEP RUPTURE TEST

CENTRAL LAB,

WRI




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Expert PanelFor RLA

Engineering& R&D Metallurgical

Analysis

NDE

Doctorates : 5Post Graduates : 50

Doctorates : 6Post Graduates : 10

Level I : 43Level II : 136

Graduates : 250 Graduates : 10 Level III : 6

eve , as per -

Techniques UT, RT, MT, PT, Eddy Current(ET), & Leak Test (LT)




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National NDT Award from ISNT 4 times

Two Registered Assessors Qualified from

ns u e o eg s ere er e

Assessors (IRCA, UK)




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spec a con r u on n e area o

Personnel, Boiler Inspectorate Personnel and

Customers Personnel HRD Training Program on RLA Being

Conducted for Education of BHEL En ineers

Customer Engineers & Boiler Inspectors WRI & BHEL Indo-German Pro ram

Encompasses RLA also

Boilers Including Piping & Industrial Boilers &

other Com onents




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(cont.)

Training of BHEL executives in the field of RLA at

,

Field Training at Chandrapura TPS by EPRI, USA

o er ea er o ca on w

Material Based on Assessment by RLA Techniques

Being Met When Called for

SAIL, Bokaro in Full Agreement Technically




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Special NDT techniques developed by BHEL

Detection of hydrogen damage by UT Measurement of oxide scale thickness by

.

Microstructural evaluation by replication

A new technique called VAPINE'.

by UT.




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Post Ex osture Uni-Axial Accelerated cree testin

In-Situ Hardness Tester

-

Digital Strain Measurement Gauge

Portable Microscope for Insitu MetallurgicalExamination

Portable Alloy Analyser

with microprocessor




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Unique Test Facilities at BHEL (Cont)

Impact test facility up to minus 196 deg C

Scanning Electron Micro Scope

Atomic Absorption Spectrometer Portable Stress Anal ser

Video Fibrescope




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Scannin Electron Micro Sco e




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-




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Li ament Crack Detection b UT




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ecommen at ons ormat yp ca

Residual life ins ection intervals of components

ar s nee ng rep acemen s

Parts needin re airs

Chemical cleaning advice & procedure

o cat ons requ re or e extens on




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Advice on water regimes Improvements in operational methods

Retrofits / improvements in control &

instrumentation




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stu es arr e out y

Total Number of studies carried out : 208Power Boilers : 138

Process/Industrial Boilers : 70




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Run Repair Replace

RLA

Evaluates For All Phases



Currentworking ofBHELin the RLA Field


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Current working of BHEL in the RLA Field

Working on a comprehensive Advanced RLA software to evaluate pressure part creep and Fatique life

assessment called ALIAS.

and accurate. Planning to use in site with data

.

Strain measurement to Evaluate the safety factor of

Drum as per ASME code Section 8UG L101.

Drum with the ASME design safety margin for the


.



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Life Assesment of Boilers

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