Overview Heat Recovery Steam Generators

Bharat Heavy Electricals Limited TIRUCHIRAPALLI

Boiler Performance & Proposals – FBC & HRSG

Heat Recovery Steam GeneratorsHeat Recovery Steam Generators



What is HRSG / WHRB ?What is HRSG / WHRB ?

HRSG : Heat Recovery Steam Generator Recovers heat energy available in GT

Exhaust and Generates Steam WHRB : Waste Heat Recovery Boiler

Recovers heat energy available in the Waste Gases from various Processes

Flue Gas out

Steam out

Feed water in

HRSG or

WHRBFlue Gas in



Heat Recovery Steam GeneratorsHeat Recovery Steam Generators behind Gas Turbinesbehind Gas Turbines



Why HRSG ?Why HRSG ?



HRSG ApplicationsHRSG Applications

HRSGs are used in:

Combined Cycle Power Plants to provide steam

to a steam turbine

Cogeneration Plants to provide steam for

industrial processes

Combined Cycle Cogeneration Plants to provide

steam to a steam turbine and the extraction

from steam turbine is used for industrial

processes



Efficiency LevelsEfficiency Levels



Combined Cycle ApplicationCombined Cycle Application



Combined Cycle PlantCombined Cycle Plant



Popular Gas TurbinesPopular Gas Turbines



No of HRSGs supplied to No of HRSGs supplied to Combined cycle plants by BHELCombined cycle plants by BHEL

Gas Turbines

GE Fr5 GE Fr6 GE Fr6FAGE Fr

9EV94.2 Others

2 14 5 7 7# 14 *

Total 49

•WH/W191(3 Nos); MES/SB30(1 No) ; MHI Fr 6 (4 Nos); ALST PG6541B(6 Nos)#4 HRSGs of Wagner Biro Design



Plant Configuration OptionsPlant Configuration Options



100 MW Plant Configuration Options100 MW Plant Configuration Options

Fr6 GT 2P HRSG

STG

Fr6 GT 2P HRSG

Fr6FA GT 3P HRSG STG



350 MW Plant Configuration Options350 MW Plant Configuration Options

Fr9E GT 2P HRSG

STG

Fr9E GT 2P HRSG

Fr9FA GT 3PR HRSG STG



1300 MW Plant Configuration1300 MW Plant Configuration

Fr9FA GT 3PR HRSG

STG

Fr9FA GT 3PR HRSG

Fr9FA GT 3PR HRSG

STG

Fr9FA GT 3PR HRSG



Heat Recovery Steam Generators Heat Recovery Steam Generators

forfor

Gas Turbines upto 60 MWeGas Turbines upto 60 MWe



HRSGs behind Fr 5 GT HRSGs behind Fr 5 GT

Parameters

t/h kg/cm2 °C

32.5 MW

1GT+1HRSG+1ST

In operation from

19991 HP 48.3 45.5 390PPCL, Karaikal

Pressure Level

Power OutputCustomer No of units



HRSGs behind Fr 6 GT HRSGs behind Fr 6 GT Parameters

t/h kg/cm2 °C

98 MW HP 59.3 62 483

2GTs+2HRSGs+1ST LP 10.8 5 SAT

146 MW HP 58.4 62 483


97 MW HP 59.5 62 483

2GTs+2HRSGs+1ST LP 11 5 SAT

146 MW HP 57.5 62 483


103 MW

2GTs+2HRSGs+1ST

109 MW HP 60.1 80 520

2GTs+2HRSGs+1ST LP 15.4 6 200

In operation from

1990

1990

2

3

AECO, Vatwa

Pressure Level

2

Power OutputCustomer No of units

GIPCL, Baroda

APSEB, Vijjeswaram

GEB, Utran

NEEPCO, Kathalguri

RVUNL, Ramgarh

2 HP 59.7

1990

3 1991

2 2003

199441 473




for for

Higher Capacity Gas Turbines Higher Capacity Gas Turbines

(60 – 160 MWe)(60 – 160 MWe)



Triple Pressure HRSGs behind Fr 6FA GTsParameters

t/h kg/cm2 °C

107.88 MW HP 110.6 107 537

IP 9.6 30 260

LP 8.1 6 200

105 MW HP 105.4 107 537

IP 8.6 30 260

LP 7 6 200

100 MW HP 113.1 107 537

IP 8.7 30 260

LP 7.5 6 200

100 MW HP 110.7 107 542

IP 8.2 27.5 317

LP 8.2 4.87 227

107 MW HP 118.2 107 542

IP 8.3 30 260

LP 6.6 6 200

1GT+1HRSG+1ST

1GT+1HRSG+1ST

Customer No of unitsPressure

LevelIn operation

fromPower Output

TNEB, Kovilkalappal 1 2001

TNEB, Perungulam 1 2003

1GT+1HRSG+1ST

1GT+1HRSG+1ST

GSECL, Dhuvaran Phase-II

1Under

Execution

GSECL, Dhuvaran 1 2003

TNEB, Kuttalam 1 2004

1GT+1HRSG+1ST



HRSGs behind Fr 6FA GTs HRSGs behind Fr 6FA GTs (70.14 MW ISO)(70.14 MW ISO)

1 No HRSG for 107 MW CCPP

at TNEB,Kovilkalappal,India.

Tamilnadu

Electricity

Board

Customer

LP

GT Fuels NG

Commissioning February 2001

Parameters

Steam flow t/h

Pressure kg/cm2(a)

Temperature °C

HP

110.6

200

107

8.1

537

6.0

Salient Features Top supported

Module ht 12.1m

Two width

94 Modules

IP

9.6

30

260

Tamil Nadu Electricity Board



HRSGs behind Fr 9E GTHRSGs behind Fr 9E GT

Parameters

t/h kg/cm2 °C

165 MW HP 176 80 520

1GT+1HRSG+1ST LP 45.6 6 200

350 MW HP 188.4 80 520


330 MW HP 180.2 76.6 520

2GTs+2HRSGs+1ST LP 37.1 5.8 200

330 MW HP 187.1 79.2 514


Power Output

RVUNL-Dholpur 2Under

Execution

Customer No of unitsIn operation

from

GIPCL, Baroda

Pressure Level

NTPC, Kayamkulam

DVB, Pragati

1998

1999

2003

1

2

2



Salient Features Top supported

Module ht 18.8m

CPH re-circulation

Two width

102 Modules

Customer National

Thermal Power

Corp. Ltd

Commissioning

Parameters

Steam flow t/h

Pressure kg/cm2(a)

Temperature °C

HP

39.5

80 6.0

LP

Naptha/NG/HSD

October 1999

520

HRSGs behind Fr 9E GTs HRSGs behind Fr 9E GTs (123.4 MW ISO)(123.4 MW ISO)

2 Nos HRSGs for 350MW CCPP

at NTPC,Kayamkulam,India.

GT Fuels

188.4

200



HRSGs behind V94.2 GTHRSGs behind V94.2 GT

Parameters

t/h kg/cm2 °C

817 MW HP 225.9 65.3 530

4GTs+4HRSGs+2ST LP 46.7 4.8 200

200 MW HP 226.7 79 525

1GT+1HRSG+1ST LP 46.1 6 200

400 MW HP 231 80 530


CustomerNo of units

Pressure Level

In operation from

Power Output

NTPC, Faridabad 2 2000

NTPC, Dadri 4 1992

TEC, Trombay 1 1994



226.7 46.1

80

Tata Electric

Company, Trombay

Parameters

Steam flow t/h

Pressure kg/cm2(a)

Temperature °C

Commissioning October 1994

7.0

525

Salient Feaures Bottom supported

Module ht 16.3m

Three width

HRSG for 200 MW CCPP at TEC,Trombay,India.

Customer

LP

GT Fuels NG/HSD/Naphtha

HP

200

Dual Pressure HRSG Dual Pressure HRSG behind V94.2 GT behind V94.2 GT (157 MW ISO)(157 MW ISO)




forfor

Advanced Class Gas TurbinesAdvanced Class Gas Turbines



Triple Pressure Reheat HRSGTriple Pressure Reheat HRSG

• For maximum heat recovery from GT exhaust & better Combined

Cycle Heat Rate

• HP Steam to ST

• IP Steam to CRH or GT Injection ; HRH Steam to ST

• LP Steam to Deaerator / ST



Arrangement of Reheat SystemArrangement of Reheat System

HP IP LP

HP Drum

HPSH

II

RH

II

HPSH

IB

RH

I

HPSH

IA

HPEV

HPEC

II

IP Drum

IPEV

IPEC

LP Drum

LPSH

LPEV

IPSH

HPEC

I

CPH

HP Main Steam

Cold Reheat

Hot Reheat

IP Main Steam LP Main Steam



Reheat SystemReheat System

Ideally Suited for Advanced Class GTs due to the high level of GT exhaust flow and temperature

FeaturesFeatures

• Identical steam temperature for both HP Superheater / Reheater

• Sandwiching of Superheater and Reheater sections

• Optimum steam side pressure drop

• Cascaded Bypass system for Reheater for

• Normal Start up / Shut down

• Upset conditions like rapid load rejection and unit trip



Reheater ArrangementReheater Arrangement

HP Drum

IP SteamHP Stea

m

Hot RH

Steam

Cold RH

Steam



Steam ParametersSteam Parameters

For Combined Cycle System, Optimum Steam Pressure and

temperature levels for Triple Pressure Reheat System are

• HP : 120-130 bar and 535-565°C

• RH : 28-30 bar and 535-565°C

• LP : 4-7 bar and 200-230 °C

• Steam Flow rates for three Pressure levels are decided based on

optimum pinch and approach temperatures



Co-generation Application Co-generation Application



Fired Cogeneration PlantFired Cogeneration PlantWith FD Fan Mode OptionWith FD Fan Mode Option

Fuel

HRSGExhaust

Ste

am t

o p

roce

ss

AirG

T

Exh

aust

Fee

d

wat

er

FD FanA

irF

uel

Fresh Air



Supplementary Fired HRSGSupplementary Fired HRSG



Natural gas

Naphtha

HSD

Kerosene

Light Diesel Oil

Intermediate Fuel Oil (Residual Oil)

Other distillate fuel oils ( LSHS etc )

Fuels For Supplementary FiringFuels For Supplementary Firing



Duct Burner(Gas) ArrangementDuct Burner(Gas) Arrangement



Duct Burner(Oil) ArrangementDuct Burner(Oil) Arrangement



No of HRSGs supplied to No of HRSGs supplied to Industrial customers by BHELIndustrial customers by BHEL

GE Fr3 GE Fr5 GE Fr6 Other GTs

Unfired Fired Unfired Fired Unfired Fired Unfired Fired

- 6 6 21 - 24 1* 5#

HRSGs behind Gas Turbines 63

HRSGs for other applications 9@

•ALST/MS 5001; # JBE/Fr5(2Nos); MES/SB60(3Nos) @ sponge iron plant

Upto HPCL-Visakh



HRSGs behind Fr 5 GTs (26.3 MW HRSGs behind Fr 5 GTs (26.3 MW ISO)ISO)

2 Nos HRSGs

for IOCL, Barauni

Customer Indian Oil Corporation Ltd

Plant Barauni

Parameters Steam flow, t/h 48.2Pressure , kg/cm2(a) 40Temperature, °C 440GT Fuel Naptha/Gas/HSD HRSG Fuel Unfired

Commissioned in 2001

Salient Features Module ht 10.4m Single width 21 Modules



HRSG With FD Fan Mode

HRSG behind Fr5 GT with FD Mode HRSG behind Fr5 GT with FD Mode OptionOption

Customer

Plant

Parameters GT+SF Mode

FD Mode

Steam flow, t/h 62 64.8

Pressure , kg/cm2(a) 46 46

Temperature, °C 443 443

GT Fuel

HRSG Fuel

Commissioned in

Salient Features

Oil & Natural Gas Corporation Ltd

Gandhar

NG

Fuel Gas

1997

Module ht 8.3m

Single width

27 Modules



13 Nos HRSG for RIL-Patalganga/ Hazira / Jamnagar, India.

Duct Fired HRSG behind Fr 6 GT Duct Fired HRSG behind Fr 6 GT (38.34 MW (38.34 MW ISO)ISO)

Steam Drum

GT Exhaust

ECO

EVAP

SH

DB

SH

Customer

Plant PG Hazira Jamnagar

Parameters Steam flow, t/h 125 125 125Pressure , kg/cm2(a) 105 118 116Temperature, °C 500 512 510GT FuelHRSG Fuel

Commissioned in 1995 1996-99 1999

Salient Features

(~3 times unfired output)

66 Modules

125 tph even at 20MW GT load

Reliance Industries Ltd

NG/Naptha/HSD NG/Naptha / HSD / Kerosene

Module ht 8.3m Two width



Duct Fired HRSG behind Fr 6 GT Duct Fired HRSG behind Fr 6 GT (38.34 (38.34 MW ISO)MW ISO)

1 No HRSG behind Fr 6 GT for IPCL-Gandhar

GT Exhaust

ECOEVAPSH

Steam Drum

DB

FD Fan

Customer

PlantGT+SF Mode FD Mode

Parameters Steam flow, t/h 100 100Pressure , kg/cm2(a) 108 108Temperature, °C 513 513GT FuelHRSG Fuel

Commissioned in

Salient Features

56 Modules MCR Steam Output Even in FD Mode Duct burner for 90Mkcal/h

Indian Petrochemicals Ltd

Naptha/HSD Naptha / HSD / LDO

1997

Module ht 8.3m Two width

Gandhar



4 Nos HRSGs for IOCL-Panipat Integrated Power Plant, India.

MUHECOEVAPSH

Steam DrumMembrane Wall Water Cooled

Furnace

GT Exhaust

Furnace Fired HRSGs behind Fr 6 GTs Furnace Fired HRSGs behind Fr 6 GTs (39.62 MW (39.62 MW ISO)ISO)

Customer Indian Oil Corporation Ltd

Plant Panipat

Parameters Steam flow, t/h 110Pressure , kg/cm2(a) 48Temperature, °C 405GT Fuel Naptha/HSD HRSG Fuel IFO / HSD

Commissioned in 2001

Salient Features Module ht 12.1m Single width 40 Modules Furnace Fired HRSG



HRSGs Vs Conventional BoilersHRSGs Vs Conventional Boilers



HRSGs Vs Conventional BoilersHRSGs Vs Conventional BoilersIn HRSGs GT exhaust is the main heat source - no need for a firing

system(unless supplementary fired).

Positive pressure of GT exhaust provides draft – no need for fans (except FD Mode)

Steam generation at multiple pressure levels

Heat transfer is predominantly through convection

HRSGs do not generally use membrane wall construction

Finned tubes used for compactness and maximum heat transfer



HRSGs-ClassificationHRSGs-Classification

Firing Unfired Duct Fired Furnace Fired

Circulation Natural Assisted / Forced Once -Through

Gas flow direction Horizontal Vertical

Construction Modular Coil Design

Width

Pressure Levels Single Multiple

Single Double Triple

Reheater Reheat Non-Reheat



BHEL HRSGs - Road MapBHEL HRSGs - Road Map

1977 : First HRSG for Namrup, Assam - Based on In house Design

1982 : First Supplementary Fired HRSG for ONGC, Uran - In house design

1986 : First Furnace Fired, Dual Pressure HRSG with FD mode for ONGC-Hazira (Fr5 GT)

1988* : Technical Collaboration with

1989 : Auto Trip Transfer established within 1 minute at ONGC-Hazira

1991 : First Dual Pressure Triple width HRSG behind V94.2 GT for TEC-Trombay

1999 : First Triple Pressure HRSG behind Fr 6FA GT for TNEB-Kovilkalappal

2003 : First Furnace fired HRSG for firing Heavy Fuel Oil for IOCL-Panipat

* Extended upto 2010



ALST-Alsthome Atlantique, France

JBE-John Brown Engg, UK

MHI-Mitsubishi Heavy Industries, Japan

MES-Mitsui Engg & Shipbuilding, Japan

WHRB (Sponge Iron) - 9Combined Cycle - 49 CogenerationUnfired - 7 Supplementary Fired - 56

Total - 121

BHEL Experience - HRSGs & WHRBs BHEL Experience - HRSGs & WHRBs



Features of BHEL HRSGsFeatures of BHEL HRSGs

Triple Pressure Reheat Natural circulation Horizontal configuration Modular construction Fully drainable sections Top Supported Complete internal insulation Composite Angle Inlet Transition duct Despatched as Loose Modules Insulation at Site



Modular ConstructionModular Construction

Two Row Module

Single Row Module



Arrangement of ModulesArrangement of Modules



DESH

SH Evaporator Economiser

Arrangement of HRSGArrangement of HRSG



Natural Circulation HRSGNatural Circulation HRSG

Horizontal Gas Flow

Vertical Tubes



Internal InsulationInternal Insulation

Outer Duct Casing

Internal Insulation

Liner Plates

Flue Gas Path



Manufacturing Facilities Manufacturing Facilities

for for

HRSGHRSG



Shop facilitiesShop facilities



Facility created for larger size HRSG Module

Fabrication

Special facilitiesSpecial facilities

Module Height – Upto 26 m



Waste Heat Recovery BoilerWaste Heat Recovery Boiler

For Process PlantsFor Process Plants



Applications of WHRB

Recovering Heat in Industrial Exhausts from

Iron & Steel Plants

Copper / Zink Smelter Plants

Diesel Engines

Cement Plants

Chemical / Fertiliser Plants



Sl No

Customer Contract

Year Units Steam Parameters Fuel Heat Source Status

Flow (t/h) Pressure (ata)

Temp (°C)

1 Prakash Industries Ltd, Chamba., MP

1991 1 46.8 53 410 Unfired Sponge Iron Kiln Exhaust

In Operation since 1993

2 Prakash Industries Ltd, Chamba., MP



3

Sunflag Iron & Steel Co., Bhandra, Nagpur

Maharastra.



4 Bhushan Steel & Strips Ltd, Meramandali, Orissa


Under Execution

5 Jindal Stainless Ltd, Dubri Orissa

2004 2 28.5 42 405 Unfired Ferro Chrome Kiln Exhaust

Under Execution

BHEL’s WHRBs



Typical General Arrangement of WHRB System for Sponge Iron Plant



Arrangement of WHRB



Salient Features of BHEL WHRBs

Single Drum, Natural circulation & Top Supported design

Fully drainable heat transfer sections with Horizontal / Inclined

tubes

Two stage Superheater with interstage spray type attemperator

Non steaming Economiser

Economiser recirculation system

Induced Draft fan

Electrostatic Precipitator (ESP)



Salient Features of BHEL WHRBs

Features for handling sticky dust laden (~ 65 g/Nm3) kiln exhaust gas

at high temperature (~1000°C)

Fusion / Fin welded membrane wall construction

Radiation chamber at inlet for reducing the gas temperature

Plain tube heat transfer sections

Inline Tube Arrangement

Inter-Bank Soot blowers for on-load cleaning

Cassette baffles to protect economiser coil bends from erosion

No convective sections in First pass & superheater, Evaporator

and economiser located in second/third passes

Single / Multipass vertical (Downward and Upward) gas flow

passes to enable positive dust settlement through hoppers



Design Design

&&

Operational AspectsOperational Aspects



Superheater

Evaporator

Economiser

Flue Gas

Pinch PointApproach Point

Te

mp

era

ture

HRSG Inlet HRSG Outlet

HRSG Temperature ProfileHRSG Temperature Profile



Optimum Pinch & Approach Optimum Pinch & Approach TemperaturesTemperatures

Higher Pinch Point Lower Steam Qty - Less Material - Cheaper HRSG

Lower Pinch Point Higher Steam Qty - More Material - Costlier HRSG

Optimum Pinch Point (5 To 10 Deg.C)

Higher Approach Point Lower Steam Qty - Less Material - Cheaper HRSG Steaming At Part Loads - Less likely

Lower Approach Point Higher Steam Qty - More Material - Costlier HRSG Steaming At Part Loads - More likely

Optimum Approach Point (5 to 10 Deg.C)



Pinch Point Pinch Point



Approach Point Approach Point



Optimisation of Heat Transfer Sections Optimisation of Heat Transfer Sections Arrangement Arrangement



Unique aspects in HRSG DesignUnique aspects in HRSG Design

HRSG is a slave system – No direct control over inputs

More than one HRSG feeding a Single Steam Turbine (2-

2-1)

Multiple Pressure levels

Sliding pressure operation

Condensate / makeup water heating

Protection against water / acid condensation

Balancing the requirements at unfired / GT+SF / FD

modes



GT CharacteristicsGT Characteristics

GT output / exhaust

parameters depend on

Ambient Temperature

RH

Site Elevation

Back Pressure

Inlet Air cooling System

Injection

Combustor Type

IGV position



Multiple Pressure Levels & Reheat Multiple Pressure Levels & Reheat SystemSystem

Single Pressure Non Reheat

% Efficiency : ~38-42

Dual Pressure Non Reheat


Widely Used

Triple Pressure Non Reheat


Triple Pressure Reheat

% Efficiency : 55-58 (Single RH) / 60 (Double

RH)

For Advanced Class Gas Turbines



CPH / Deaerator SystemCPH / Deaerator System

Condenser

ST

CPH

CEP

GSCHP BFP

IP BFP

LP BFP

To HP Eco

To IP Eco

To LP Eco

HRSG

LP Steam



CPH with Recirculation SystemCPH with Recirculation Systemfor Protection of CPH against Dew Point Corrosion

From Condenser

To Deaerator



HRSG Start-up ConsiderationsHRSG Start-up Considerations

Temperature difference across thick walled components

Thermal stresses

Pressure stresses

Thermal stress plus pressure stress < Max. allowable

stress



HRSGs for CCPP - Present TrendHRSGs for CCPP - Present Trend

Dual / triple pressure levels

Very high pressure

High superheat temperature

Low pinch Point

Close approach Temperature



HRSGs for Co-gen Plants - Present HRSGs for Co-gen Plants - Present TrendTrend

Increased steam demand / High supplementary firing

Higher steam pressure and temperature

Duct burner located between heat transfer surfaces

SH steam temperature over a wide operating range



HRSGs for Co-gen Plants - Present HRSGs for Co-gen Plants - Present TrendTrend

MCR steam output even at GT Part load

Introduction of SF at low GT loads

MCR steam output even in forced draft fan mode

Auto Trip Transfer

Non steaming economiser for a wide operating range

CPH to meet plant condensate requirements

Heavy Fuel Oil / Blended Fuel Oil Firing



Future TrendsFuture Trends Advanced Class GTs - 200 MW and above

Reheat Cycle

Stringent Environmental Regulations Nox : < 25 ppm with gas firing < 65 ppm with Liquid fuels

Design for Two-shift operation / Cycling

Auto Plant Startup / Auto Plant Regulation

State - of - art C & I

Two stage supplementary firing

Supplementary firing in HRSGs behind large GTs



ImprovementsImprovements



Continuous Design ImprovementsContinuous Design Improvements

• In-house Developments & Analyses

• Joint Work with Educational Institutions (IIT)

• Seminars and International Conference

• Operational feedback from more than 100 HRSGs

• Feed back from manufacturing & Erection groups



In-house Developments & In-house Developments & AnalysesAnalyses

• Scaled down model Study done In-house for

• Gas flow distribution in HRSGs

• Steam flow distribution in Superheater Modules

• CFD Modeling

• Design of Flow Distribution Grid

• Composite Angle Inlet Transition Ducting

• Steam Flow Distribution

• Increased No. of nozzles for better steam distribution in Superheater modules



Scale Down Model for Analysis of Scale Down Model for Analysis of Gas Flow Distribution in HRSG Gas Flow Distribution in HRSG

DuctDuct



Preferential Flow Pattern in Straight Transition Duct

Streamlined Flow pattern in Composite Angle Duct

Optimisation of HRSG Inlet transition Optimisation of HRSG Inlet transition ductduct

Uniform Flow Pattern in Straight Transition Duct with Distribution Grid



Grid Plate Constructed with Flat StripsGrid Plate Constructed with Flat Strips

Horizontal Strips

Outer Duct Casing

Internal Insulation

SS Liner



Cold Flow Study of Cold Flow Study of Steam Flow Distribution in ModulesSteam Flow Distribution in Modules



Results of Scaled down 3D Water flow model studies

0.7

0.8

0.9

1

1.1

1.2

1.3

0 5 10 15 20 25TUBE No.

VA

RIA

TIO

N

Single pass - Top row

Single pass - Bottom row

Four pass -Top row

Four pass -Bottom row



Effect of number / location of nozzles Effect of number / location of nozzles on Steam Flow Distributionon Steam Flow Distribution

Low velocity region

High velocity region

Uniform velocity



Further Improvements implemented in Further Improvements implemented in current HRSGscurrent HRSGs

Adoption of Single row module

Adoption of smaller header for reduced thermal stress and fatigue

damage

Adoption of composite angle inlet transition duct and gas

distribution grid constructed of flat strips

Insulation of HRSG Casing done at site for reducing Erection Time



Modules with single row tube will

eliminate additional bending stresses

due to offset tube to header welds

Adoption of single row Adoption of single row modulemodule



Site Feedback Site Feedback

…Strategy adopted at… has considerably compressed the erection time… Insulation of casings done in site …



Single row modules Better welding access & Ease of Manufacture

Smaller headers Reduced header diameter & thickness, Reduced stress levels

Increased number & proper location of inlet nozzles Uniform flow distribution/metal temperatures, reduced

differential expansion between tubes in a module

Flexible connecting piping Adequate flexibility in interconnecting piping to ensure

unrestricted expansion of heat transfer modules

Adequately sized drains & vents For quick draining/venting of all modules To minimise thermal shock in superheater

Operational Flexibility of BHEL HRSGsOperational Flexibility of BHEL HRSGs



Thank You Thank You

Overview Heat Recovery Steam Generators

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