44962346 Heat Recovery Steam Generators

5/21/2018 44962346 Heat Recovery Steam Generators

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Bharat Heavy Electricals LimitedTIRUCHIRAPALLI

Boiler Performance & ProposalsFBC & HRSG

Heat Recovery Steam Generators


2/94



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


3/94



Heat Recovery Steam Generatorsbehind Gas Turbines


4/94



Gas turbine basedSimpleCycle

CombinedCycle

CogenCombined

Cycle CogenConventionalBoiler & STG

35-40 23-42 38

60 75 - 90 50 - 70

Why HRSG ?


5/94



HRSG Applications

HRSGs are used in:

Combined Cycle Power Plantsto provide steam to a

steam turbine

Cogeneration Plantsto provide steam for industrial

processes

Combined Cycle Cogeneration Plantsto provide steam

to a steam turbine and the extraction from steam

turbine is used for industrial processes


6/94



Efficiency Levels

Gas turbine basedSimple

Cycle

Combined

CycleCogen

Combined

Cycle Cogen

Conventional

Boiler & STG

35-40 23-42 3860 75 - 90 50 - 70


7/94



Combined Cycle Application


8/94



Combined Cycle Plant


9/94



Popular Gas TurbinesModel Power

MW (ISO)

GE

G3142(J) Fr 3 10.45

PG5371(PA) Fr 5 26.3PG6561(B) Fr 6 42.1

PG6101(FA) Fr 6FA 70.14

PG9171(E) Fr 9E 123.4

PG9351 (FA) Fr 9FA 255.6

Siemens

V94.2 V94.2 157

V94.2A V94.2A 190

V94.3A V94.3A 265


10/94



No of HRSGs supplied to

Combined cycle plants by BHEL

Gas Turbines

GE Fr5 GE Fr6 GE Fr6FA GE Fr 9E V94.2 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


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MODEL GT Power (MW)HRSG Output

(Approx.)

ST Power

(Approx.)

CCP Power

(Approx.)

ISO Site (~) TPH MW MW

G3142(J) Fr3 10.45 9 20 5 14

PG5371(PA) Fr5 26.3 20 40 10 30

PG6561(B) Fr6 42.1 33 58+14 22 55

PG6101(FA) Fr6FA 70.14 65 110+8+8 35 100

PG9171(E) Fr9E 123.4 105 185+35 60 165

V94.2 V94.2 157 140 230+45 80 220

PG9351(FA) Fr9FA 255.6 220 270+45+30 110 330

Plant Configuration Options


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100 MW Plant Configuration Options

Fr6 GT 2P HRSG

STG

Fr6 GT 2P HRSG

Fr6FA GT 3P HRSG STG


13/94



350 MW Plant Configuration Options

Fr9E GT 2P HRSG

STG

Fr9E GT 2P HRSG

Fr9FA GT 3PR HRSG STG


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1300 MW Plant Configuration

Fr9FA GT 3PR HRSG

STG

Fr9FA GT 3PR HRSG

Fr9FA GT 3PR HRSG

STG

Fr9FA GT 3PR HRSG

Bh t H El t i l Li it d


15/94




for

Gas Turbines upto 60 MWe



16/94



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

LevelPower OutputCustomer No of units



17/94



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

3GTs+3HRSGs+3ST LP 12.4 5 SAT

97 MW HP 59.5 62 483

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

146 MW HP 57.5 62 483

3GTs+3HRSGs+3ST LP 11.5 5 SAT103 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



18/94




for

Higher Capacity Gas Turbines

(60160 MWe)



19/94



Triple Pressure HRSGs behind Fr 6FA GTs

Parameters

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

Level

In operation

fromPower Output

TNEB, Kovilkalappal 1 2001

TNEB, Perungulam 1 2003

1GT+1HRSG+1ST

1GT+1HRSG+1ST

GSECL, Dhuvaran

Phase-II 1

Under

Execution

GSECL, Dhuvaran 1 2003

TNEB, Kuttalam 1 2004

1GT+1HRSG+1ST

Bharat Heavy Electricals Limited


20/94


TIRUCHIRAPALLI


HRSGs behind Fr 6FA GTs (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

Bharat Heavy Electricals Limited TIRUCHIRAPALLI


21/94


TIRUCHIRAPALLI


HRSGs 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 200330 MW HP 187.1 79.2 514


Power Output

RVUNL-Dholpur 2 Under

Execution

Customer No of units In operation

from

GIPCL, Baroda

Pressure

Level

NTPC, Kayamkulam

DVB, Pragati

1998

1999

2003

1

2

2



22/94


TIRUCHIRAPALLI


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/cm

2

(a)Temperature C

HP

39.5

80 6.0

LP

Naptha/NG/HSD

October 1999

520

HRSGs behind Fr 9E GTs (123.4 MW ISO)

2 Nos HRSGs for 350MW CCPP

at NTPC,Kayamkulam,India.

GT Fuels

188.4

200



23/94


TIRUCHIRAPALLI


HRSGs 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 5302GTs+2HRSGs+1ST LP 46.3 5 200

Customer No of

units

Pressure

Level

In operation

fromPower Output

NTPC, Faridabad 2 2000

NTPC, Dadri 4 1992

TEC, Trombay 1 1994



24/94


TIRUCHIRAPALLI


226.7 46.1

80

Tata ElectricCompany, 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

behind V94.2 GT (157 MW ISO)



25/94


TIRUCHIRAPALLI



for

Advanced Class Gas Turbines



26/94


TIRUCHIRAPALLI


Triple 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



27/94


TIRUCHIRAPALLI


Arrangement of Reheat System

HP IP LP

HP

Drum

HP

S

H

II

R

H

II

HP

S

H

IB

R

H

I

HP

S

H

IA

H

P

E

V

HP

E

C

II

IP

Drum

I

P

E

V

I

P

E

C

LP

Drum

L

P

S

H

L

P

E

V

I

P

S

H

HP

E

C

I

C

P

H

HP Main Steam

Cold Reheat

Hot Reheat

IP Main Steam LP Main Steam



28/94


TIRUCHIRAPALLI


Reheat System

Ideally Suited for Advanced Class GTs due to the high level of GT

exhaust flow and temperature

Features

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



29/94


TIRUCHIRAPALLI


Reheater Arrangement

HP

Drum

IP SteamHP

Stea

m

Hot RH

Steam

Cold RH

Steam



30/94


TIRUCHIRAPALLI


Steam Parameters

For Combined Cycle System, Optimum Steam Pressure andtemperature levels for Triple Pressure Reheat System are

HP : 120-130 bar and 535-565C

RH : 28-30 bar and 535-565C

LP : 4-7 bar and 200-230 C

Steam Flow rates for three Pressure levels are decided based on

optimum pinch and approach temperatures



31/94


TIRUCHIRAPALLI


Co-generation Application



32/94



Fired Cogeneration PlantWith FD Fan Mode Option

Fuel

HRSG

Exhaust

Air

FD Fan

Fresh Air



33/94



Supplementary Fired HRSG



34/94

y


Natural gas

Naphtha

HSD

Kerosene

Light Diesel Oil

Intermediate Fuel Oil (Residual Oil)

Other distillate fuel oils ( LSHS etc )

Fuels For Supplementary Firing



35/94

y


Duct Burner(Gas) Arrangement



36/94

y


Duct Burner(Oil) Arrangement



37/94

y


No of HRSGs supplied to

Industrial 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



38/94

y


HRSGs behind Fr 5 GTs (26.3 MW ISO)

2 Nos HRSGs

for IOCL, Barauni

CustomerIndian Oil

Corporation Ltd

Plant Barauni

Parameters

Steam flow, t/h 48.2Pressure , kg/cm2(a) 40

Temperature, C 440

GT Fuel Naptha/Gas/HSD

HRSG Fuel Unfired

Commissioned in 2001

Salient Features Module ht 10.4m

Single width

21 Modules


TIRUCHIRAPALLI


39/94


HRSG With FD Fan Mode

HRSG behind Fr5 GT with FD Mode Option

Customer

Plant

ParametersGT+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 LtdGandhar

NG

Fuel Gas

1997

Module ht 8.3m

Single width

27 Modules


TIRUCHIRAPALLI


40/94


13 Nos HRSG for RIL-Patalganga/

Hazira / Jamnagar, India.

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

Steam Drum

GT

Exhaust

E

C

O

E

V

A

P

S

H

D

BS

H

Customer

Plant PG Hazira Jamnagar

Parameters

Steam flow, t/h 125 125 125

Pressure , kg/cm2(a) 105 118 116

Temperature, C 500 512 510

GT Fuel

HRSG 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


TIRUCHIRAPALLI


41/94


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

1 No HRSG behind Fr 6 GT

for IPCL-Gandhar

GT

Exhaust

ECOEVAPSH

SteamDrum

DB

FD Fan

Customer

Plant

GT+SF Mode FD Mode

Parameters

Steam flow, t/h 100 100

Pressure , kg/cm2(a) 108 108

Temperature, C 513 513GT Fuel

HRSG 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


TIRUCHIRAPALLI


42/94


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 (39.62 MW ISO)

CustomerIndian Oil

Corporation Ltd

Plant Panipat

Parameters

Steam flow, t/h 110

Pressure , kg/cm2(a) 48Temperature, C 405

GT Fuel Naptha/HSD

HRSG Fuel IFO / HSD

Commissioned in 2001

Salient Features Module ht 12.1m

Single width

40 Modules

Furnace Fired

HRSG


TIRUCHIRAPALLI


43/94


HRSGs Vs Conventional Boilers

HRSGConventional

Boilers

Gas/Steam Ratio 3.5-7.0 1.0-1.2

Gas Inlet Temp. C < 650 >1200


TIRUCHIRAPALLI


44/94


HRSGs Vs Conventional Boilers

In HRSGs

GT exhaust is the main heat source - no need for a firing system(unlesssupplementary fired).

Positive pressure of GT exhaust provides draft no need for fans (exceptFD 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


TIRUCHIRAPALLI


45/94


HRSGs-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


TIRUCHIRAPALLI


46/94


BHEL HRSGs - Road Map

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

1982:First Supplementary FiredHRSG for ONGC, Uran - In housedesign

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

1988*:Technical Collaboration with

1989:Auto Trip Transferestablished within 1 minute at ONGC-Hazira

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

1999:First Triple PressureHRSG behind Fr 6FA GTfor TNEB-Kovilkalappal

2003:First Furnace firedHRSG for firing Heavy Fuel Oilfor IOCL-Panipat

* Extended upto 2010


TIRUCHIRAPALLI


47/94


3

2

6

21

24

31

4

1

6

5

7

79

8

14

0 2 4 6 8 10 12 14 16 18 20 22 24 26

Westinghouse-W191MES-SB30

MES-SB60

MHI-Fr6

JBE-Fr 5

ALST-MS5001

ALST-Fr 6GE/BHEL-Fr 3

GE/BHEL-Fr 5

GE/BHEL-Fr 6

GE/BHEL-Fr 6FA

GE/BHEL Fr 9E

Siemens-V 94.2Sponge Iron Kiln

Fired Unfired

ALST-Alsthome Atlantique, France

JBE-John Brown Engg, UK

MHI-Mitsubishi Heavy Industries, Japan

MES-Mitsui Engg & Shipbuilding, Japan

WHRB (Sponge Iron) - 9

Combined Cycle - 49

Cogeneration

Unfired - 7

Supplementary Fired - 56

Total - 121

BHEL Experience - HRSGs & WHRBs


TIRUCHIRAPALLI


48/94


Features 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


TIRUCHIRAPALLI


49/94


Modular Construction

Two Row Module

Single Row Module


TIRUCHIRAPALLI


50/94


Arrangement of Modules


TIRUCHIRAPALLI


51/94


DESH

SH Evaporator Economiser

Arrangement of HRSG


TIRUCHIRAPALLI


52/94


Natural Circulation HRSG

Horizontal Gas Flow

Vertical Tubes


TIRUCHIRAPALLI


53/94


Internal Insulation

Outer Duct Casing

Internal Insulation

Liner Plates

Flue Gas Path


TIRUCHIRAPALLI


54/94


Manufacturing Facilities

for

HRSG


TIRUCHIRAPALLI


55/94


Shop facilities


TIRUCHIRAPALLI


56/94


Shop facilities


TIRUCHIRAPALLI

S i l f iliti


57/94


Facility createdfor larger size

HRSG Module

Fabrication

Special facilities

Module HeightUpto 26 m


TIRUCHIRAPALLI


58/94


Waste Heat Recovery BoilerFor Process Plants


TIRUCHIRAPALLI


59/94


Applications of WHRB

Recovering Heat in Industrial Exhausts from

Iron & Steel Plants

Copper / Zink Smelter Plants

Diesel Engines

Cement Plants

Chemical / Fertiliser Plants


TIRUCHIRAPALLI


60/94


SlNo

CustomerContract

YearUnits Steam Parameters Fuel Heat Source Status

Flow (t/h)Pressure (ata)

Temp(C)

1Prakash Industries Ltd,

Chamba., MP

1991 1 46.8 53 410 UnfiredSponge Iron

Kiln Exhaust

In Operation

since 1993

2Prakash Industries Ltd,Chamba., MP

1994 1 46.8 53 410 UnfiredSponge IronKiln Exhaust

In Operationsince 1996

3

Sunflag Iron & Steel Co.,Bhandra, Nagpur

Maharastra.

1994 1 45.0 65 485 UnfiredSponge IronKiln Exhaust

In Operationsince 1998

4Bhushan Steel & StripsLtd, Meramandali,Orissa

2004 4 55.4 105 540 Unfired Sponge IronKiln Exhaust

UnderExecution

5Jindal Stainless Ltd,Dubri Orissa

2004 2 28.5 42 405 UnfiredFerro ChromeKiln Exhaust

UnderExecution

BHELs WHRBs


TIRUCHIRAPALLI


61/94


Typical General Arrangement of

WHRB System for Sponge Iron Plant


TIRUCHIRAPALLI


62/94


Arrangement of WHRB


TIRUCHIRAPALLI


63/94


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)


TIRUCHIRAPALLI


64/94


Salient Features of BHEL WHRBs

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

at high temperature (~1000C)

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


TIRUCHIRAPALLI


65/94


Design

&Operational Aspects


TIRUCHIRAPALLI


66/94


Superheater

Evaporator

Economiser

Flue Gas

Pinch Point

Approach Point

HRSG Inlet HRSG Outlet

HRSG Temperature Profile


TIRUCHIRAPALLI


67/94


Optimum Pinch & Approach Temperatures

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)


TIRUCHIRAPALLI


68/94


Pinch Point

Pinch Point

Steam Quantity

Material

HRSG Cost

Pinch Point Values Adopted

Optimum : 5 - 10 .C

Normal : 8 - 10 .CLow : < 8 .C


TIRUCHIRAPALLI


69/94


Approach Point

Approach Temp

Steam Quantity

Material

HRSG Cost

Eco Steaming Possibility

Approach Temperature Values Adopted

Optimum : 5 - 10CNormal : 8 - 10C

Low : < 8 C


TIRUCHIRAPALLI


70/94


Optimisation of Heat Transfer Sections Arrangement


TIRUCHIRAPALLI

Uniq e aspects in HRSG Design


71/94


Unique 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


TIRUCHIRAPALLI

GT Characteristics


72/94


GT Characteristics

GT output / exhaust parametersdepend on

Ambient Temperature

RH

Site Elevation

Back Pressure

Inlet Air cooling System

Injection

Combustor Type

IGV position


TIRUCHIRAPALLI


73/94

Boiler Performance & Proposals

FBC & HRSG

Multiple Pressure Levels & Reheat System

Single Pressure Non Reheat % Efficiency : ~38-42

Dual Pressure Non Reheat

% Efficiency : ~42-50

Widely Used

Triple Pressure Non Reheat

% Efficiency : ~50-52

Triple Pressure Reheat

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

For Advanced Class Gas Turbines


TIRUCHIRAPALLI

CPH / D t S t


74/94


FBC & HRSG

CPH / Deaerator System

Condenser

ST

CPH

CEP

GSCHP BFP

IP BFP

LP BFP

To HP Eco

To IP Eco

To LP Eco

HRSG

LP Steam


TIRUCHIRAPALLI

CPH ith R i l ti S t


75/94


FBC & HRSG

CPH with Recirculation Systemfor Protection of CPH against Dew Point Corrosion

From Condenser

To Deaerator


TIRUCHIRAPALLI


76/94


FBC & HRSG

HRSG Start-up Considerations

Temperature difference across thick walled components

Thermal stresses

Pressure stresses

Thermal stress plus pressure stress < Max. allowable stress


TIRUCHIRAPALLI


77/94


FBC & HRSG

HRSGs for CCPP - Present Trend

Dual / triple pressure levels

Very high pressure

High superheat temperature

Low pinch Point

Close approach Temperature


TIRUCHIRAPALLI


78/94


FBC & HRSG

HRSGs for Co-gen Plants - Present Trend

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


TIRUCHIRAPALLI


79/94


FBC & HRSG

HRSGs for Co-gen Plants - Present Trend

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 operatingrange

CPH to meet plant condensate requirements

Heavy Fuel Oil / Blended Fuel Oil Firing


TIRUCHIRAPALLI

Future Trends


80/94


FBC & HRSG

Future 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


TIRUCHIRAPALLI


81/94


FBC & HRSG

Improvements


TIRUCHIRAPALLI


82/94


FBC & HRSG

Continuous 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


TIRUCHIRAPALLI

In house Developments & Analyses


83/94


FBC & HRSG

In-house Developments & Analyses

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


TIRUCHIRAPALLI

Scale Down Model for Analysis of


84/94


FBC & HRSG

y

Gas Flow Distribution in HRSG Duct


TIRUCHIRAPALLI

Optimisation of HRSG Inlet transition duct


85/94


FBC & HRSG

Preferential Flow Pattern in

Straight Transition Duct

Streamlined Flow patternin Composite Angle Duct

Optimisation of HRSG Inlet transition duct

Uniform Flow Pattern in Straight

Transition Duct with Distribution Grid


TIRUCHIRAPALLI

Grid Plate Constructed with Flat Strips
http://localhost/var/www/apps/conversion/tmp/scratch_7/Distribution%20Grid.avihttp://localhost/var/www/apps/conversion/tmp/scratch_7/Composite%20Duct.avihttp://localhost/var/www/apps/conversion/tmp/scratch_7/Straight%20Duct.avi


86/94


FBC & HRSG

Grid Plate Constructed with Flat Strips

Horizontal Strips

Outer Duct Casing

Internal Insulation

SS Liner


TIRUCHIRAPALLI

Cold Flow Study of


87/94


FBC & HRSG

y

Steam Flow Distribution in Modules


TIRUCHIRAPALLI

Results of Scaled down 3D Water flow model studies


88/94


FBC & HRSG

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.

VARIAT

ION

Single pass - Top row

Single pass - Bottom row

Four pass -Top row

Four pass -Bottom row


TIRUCHIRAPALLI

Effect of number / location of nozzles


89/94


FBC & HRSG

on Steam Flow Distribution

Low velocityregionHigh velocity

region

Uniform velocity


TIRUCHIRAPALLI

Further Improvements implemented in current


90/94


FBC & HRSG

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


TIRUCHIRAPALLI

Adoption of single row module


91/94


FBC & HRSG

Modules with single row tube will

eliminate additional bending stressesdue to offset tube to header welds

Adoption of single row module


TIRUCHIRAPALLI

Site Feedback


92/94


FBC & HRSG

Site Feedback

Strategy adopted at has

considerably compressed the

erection time Insulation of

casings done in site


TIRUCHIRAPALLI

Operational Flexibility of BHEL HRSGs


93/94


FBC & HRSG

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


TIRUCHIRAPALLI


94/94

Thank You

Date post:	12-Oct-2015
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44962346 Heat Recovery Steam Generators

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