Design of HRSGs for Industrial Application & Advanced ... P... · Design of HRSGs for Industrial...

Bharat Heavy Electricals Limited TIRUCHIRAPALLI

9th Energy Efficiency Summit 2010, Chennai Session I (3rd Sep 2010)

Design of HRSGs for Design of HRSGs for

Industrial Application & Industrial Application &

Advanced Class GTsAdvanced Class GTs

Technical Session I :Thermal System-Design, Selection &

Statutory Requirements



Overview of PresentationOverview of Presentation

Ø About HRSGs & GT based Plants

Ø HRSGs for Industrial Applications

§ Oil & Gas (Refinery /Petrochemicals / Gas)

§ Fertilizers / Chemicals

Ø HRSGs for Advanced Class GTs

§ Large Capacity, High Efficiency Combined Cycle Plants



Tube to HeaderModuleØ Natural circulationØ Horizontal configuration Ø Modular construction Ø Top SupportedØ Single row modulesØ Complete internal insulationØ Composite Angle Inlet Transition ductØ Dispatched as Loose ModulesØ Insulation at Site

Salient Features of Salient Features of HRSGsHRSGs for GT Applicationfor GT Application



BHEL Experience BHEL Experience -- HRSGsHRSGsLeading supplier in IndiaLeading supplier in India

GT Combined Cycle - 64GT Cogeneration

Unfired - 9Fired - 77

Waste Heat Recovery - 9Total - 159



Combined CyclePlant

GT ST

HRSG

CogenerationPlant

Combined Cycle Cogeneration Plant

GT ST

HRSG

Gas turbine based plant Efficiency Simple Cycle

Combined Cycle Cogen Combined

Cycle Cogen 28 - 38 % 41 – 57 % 75 – 90 % 50 – 70 %

GT

HRSG

Steam to Process

Steam to Process

Simple CycleGT Plant

TC GT

Air Exhaust Gas

GT based Plants for Maximum Efficiency from Clean FuelsGT based Plants for Maximum Efficiency from Clean Fuels



HRSGsHRSGs for Industrial Applicationsfor Industrial Applications



Options for Meeting Power/Heat requirements in IndustryOptions for Meeting Power/Heat requirements in Industry

CentralPowerPlant

Trans-mission

Standbygenerator

BoilerHeat

Demand

Cogeneration Plant

Trans-former

PowerDemand

Fuel

Fuel

Fuel

FACILITY

Export /Import Electricity

Export Heat / Steam

Fuel



Power / Steam RequirementsPower / Steam Requirements



Power & Steam Generation System OptionsPower & Steam Generation System Options

FuelSteam

Air

Flue gas

GT

HRSG

HP StmHdr

ST

TC

IP StmHdr

Boiler

LP StmHdr

PRDS

PRDS

PROCESS

• Power & Steam demands are unique for each industrial application• Power demand can be met through GT(s) or ST(s) or both • Steam demand can be met through HRSGs(s) or Boiler(s) or both



Plant operating Scenarios & their influencePlant operating Scenarios & their influenceon design/selection of Equipmentson design/selection of Equipments



Design Considerations for Cogeneration PlantDesign Considerations for Cogeneration Plant

Assessment of Power Demand(Electric load-Demand Curve)

0

5

10

15

20

25

1000 2000 3000 4000 5000 6000 7000 8000

Hours

Pow

er(M

W)

Assessment of Heat-Steam Demand(Heat load-Demand Curve)

020406080

100

1000 2000 3000 4000 5000 6000 7000 8000

Hours

Stea

m Qt

y (ton

/hr)

§ Assessment of Power Demand

§ Assessment of Steam Demand

§ Assessment of Fuels



Ø GT based cogeneration plants are preferred due to

§ Higher efficiency

§ Lower emissions

§ Faster Startup / response

Ø HRSGs are custom built to meet specific process requirements

Ø Proper definition of operating envelope of GT & HRSG are required for selecting the most suitable type among Unfired , Duct Fired & Furnace Fired HRSGs

GT Based Cogeneration Plant GT Based Cogeneration Plant



HRSG OptionsHRSG OptionsØ Unfired HRSGs are suitable only when

• Power & Steam demand fluctuations are minimal

• Dependence on steam flow, temperature from HRSG is minimum

Ø Fired HRSGs are suitable for meeting Constant/variable steam flow demand at rated steam temperature at varying

• Ambient conditions

• GT Power Output

Ø Depending on the HRSG fuels & extent of augmentation of unfired HRSG steam output, supplementary HRSGs fall into two categories

• Duct Fired HRSGs

• Furnace Fired HRSGs



Duct Fired HRSGDuct Fired HRSG

For For Gaseous FuelsGaseous Fuels

For For Liquid FuelsLiquid Fuels

01 Bypass Stack02 Diverter Damper03 Expansion Joint04 Superheater III05 Internal Insulation06 Duct Burner

07 Superheater II08 De-Superheater09 Superheater I10 Evaporator11 Economiser12 Stack

01 02 03 04 05 06 07 0908 10 11 12

Ø Suitable for nominal augmentation (~2 times unfired output) of steam output

through supplementary firing of common Liquid / Gaseous Fuels

Ø Duct burners not suitable for difficult to burn fuels

Ø Very high augmentation of steam output not possible in Duct Fired HRSGs



Furnace Fired HRSG for difficult to burn FuelsFurnace Fired HRSG for difficult to burn Fuels

ØBurners located in water cooled

membrane wall enclosure, due to

very high flue gas temperatures

ØHeat transfer bundles located

downstream in internally

insulated duct enclosure

ØSpecialised industrial burners for

difficult to burn fuels



HRSGsHRSGsfor for

Advanced Class Advanced Class GTsGTs



Evolution of Combined Cycle Units in BHELEvolution of Combined Cycle Units in BHEL



Typical Combined Cycle ParametersTypical Combined Cycle Parameters



Growth of HRSG Unit Sizes with GTGrowth of HRSG Unit Sizes with GT

Fr5 Fr6FA

Fr9E

Fr9FA

Fr6

GT Exhaust Flow (ISO) Comparison

1.0 1.17 1.66 3.34 5.29



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

HP

To Deaerator

Triple Pressure Reheat SystemTriple Pressure Reheat System



v Superior HP / RH Steam

Parameters due to superior GT

exhaust parameters

v Sandwiching of SH and Reheater

sections to achieve high HP & HRH

steam temperatures

v Proper disposition of various heat

transfer sections for optimum heat

recovery

HPSH

RH

HPSH

RH

HPSH

Sandwiching of SH & RH Sections

Triple Pressure Reheat HRSG FeaturesTriple Pressure Reheat HRSG Features



Thank You

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