01 - Boiler Performance & Design

PERCAPITA ELECTRIC POWER CONSUMPTION

COUNTRY PERCAPITA ELECTRICPOWER CONSUMPTION KWHCOUNTRY PERCAPITA ELECTRICPOWER CONSUMPTION –KWH

INDIA 367CHINA 773CANADA 16413USA 13040MEXICO 1439NORWAY 24033NORWAY 24033SWITZERLAND 7346FRANCE 7069UNITED KINGDOM 5968SPAIN 4072RUSSIA 5108ITALY 4610SWEDEN 15244SWEDEN 15244GERMANY 6406TURKEY 1259JAPAN 7749

These are collected from Ststistics Organisation for Economic Cooperation and Development of I.E.A.

GROWTH OF UNIT SIZES IN INDIA

RATING YEAR OF INTRODUCTION

GROWTH OF UNIT SIZES IN INDIA

RATING YEAR OF INTRODUCTION

30/70 MW 1965

110/120 MW 1966

200/210 MW 1972

250 MW 1991250 MW 1991

500 MW 1979

660 MW Proposal Stage

BHEL UTILITY BOILERSBHEL UTILITY BOILERSSize No. of Boilers

30MW 430MW 4

60/67.5/70/80 MW 35

100MW/110MW 45

120MW/130MW 29120MW/130MW 29

200MW 20

210MW 103

250MW 11

500MW 28

TOTAL 275

BHEL CONTRIBUTION

TOTO

POWER SECTORPOWER SECTOR

BHEL-BUILT SETS ACCOUNT FOR NEARLY 65%OF THE INDIA’S TOTAL INSTALLED CAPACITY OFOVER 1,01,000 MW

St G t St G t t t dt t dSteam Generators Steam Generators --contractedcontracted

Power Boilers:30 to 130 MW 113200/210/250 MW 130500 MW 28CFBC 2 L t 125 MW CFBC 2 Largest 125 MW HRSG 48 For GTs Fr 3, 5,6 & 9 and V 94.2Process Plant Boilers:Process Plant Boilers:Chemical Recovery 16 Largest 675 TPDConventional Firing 129 Largest 320 t/hrConventional Firing 129 Largest 320 t/hr.CFBC 1 Largest 175 t/hr.AFBC 52 Largest 165 t/hr

TotalTotal574574AFBC 52 Largest 165 t/hr

HRSG 55 Largest 127 t/hr

AS THE UNIT SIZES GREW BOILER SIZES SUPPLYING STEAM AS THE UNIT SIZES GREW BOILER SIZES SUPPLYING STEAM AS THE UNIT SIZES GREW, BOILER SIZES SUPPLYING STEAM AS THE UNIT SIZES GREW, BOILER SIZES SUPPLYING STEAM TO SUCH TURBINES HAVE ALSO INCREASEDTO SUCH TURBINES HAVE ALSO INCREASED

SIZE FLOW PRESSURE TEMPERATURE(T/H) (KG/CM2) (DEG C)(T/H) (KG/CM2) (DEG.C)

30MW 150 63 49060/70MW 260 96 540110/120MW 375 139 540/540200/210MW 690 137/156 540/540250MW 805 156 540/540500MW 1670 179 540/540

BASIC DATA FOR DESIGNBASIC DATA FOR DESIGN

BOILER PARAMTERSBOILER PARAMTERSFUEL DATASITE DATA

HEAT BALANCE DIAGRAM

505.344

190.0 814.7

535.0

HPT LPT LPT

31.07 844.8736.2 27.89BOILER

459.544 535.0335.7 459.544

0.0890

360.130

580.9

(0.9384)

234.

024

1.7

C

505.

944

-

HPH HPH

FP

D

LPH CPLPH LPH LPH

FUELS HANDLEDFUELS HANDLED

COAL/OIL/GAS IN ANY COMBINATIONLIGNITEBLAST FURNACE GAS/COKE OVEN GASCARBON MONOXIDECARBON MONOXIDECOAL TARBLACK LIQUORBLACK LIQUORBAGASSERICE HUSKRICE HUSKWASHERY REJECTSWHEAT/ RICE STRAW/ C S

FUEL ANALYSIS COAL

COAL PROPERTIES AFFECTING BOILER DESIGNCOAL PROPERTIES AFFECTING BOILER DESIGN

TYPE OF COAL ( ANTHRACITE, BITUMINOUS, LIGNITE)

HIGHER HEATING VALUEHIGHER HEATING VALUE

VOLATILE MATTER

MOISTURE CONTENT

ASH CONTENTASH CONTENT

ASH CHARACTERISTICS

HARD GROVE INDEX ( HGI )

INDIAN COALS Vs COALS OF OTHER COUNTRIESINDIA GERMA

NYUSA CANA

DAAUSTRLIA

Coal A B C RUHR WESTERN ALBERTA

NSW

MOISTURE % 15.0 12.0 12.0 8.5 16.0 4.0 8.0

VOL. % 20.0 18.0 30.0 20.5 33.0 18.0 29.0MATTERASH % 40.0 40.0 30.0 8.0 8.0 8.5 15.7

SULPHUR % 0.5 0.3 0.2 1.5 0.5 0.5 0.69

HHV KCAL/KG 3200 3500 4500 6700 5730 7600 6200HHV KCAL/KG 3200 3500 4500 6700 5730 7600 6200

COAL ASH PER MKAL KG

125 114 67 12 14 11 25KG

CHARACTERISTICS OF TYPICAL INDIAN COALCHARACTERISTICS OF TYPICAL INDIAN COAL

HIGH ASH (35 50%)HIGH ASH (35 – 50%)HIGHLY ABRASIVE (55 – 65%)MEDIUM MOISTURE (10 – 15%)MEDIUM MOISTURE (10 – 15%)MEDIUM VOLATILE MATTER (18 – 24%)LOW HEATING VALUE (HHV kcal / kg) (3000 – 3500) LOW HEATING VALUE (HHV kcal / kg) (3000 3500) LOW SULPHUR (0.2 – 0.5%)

PROBLEMS ASSOCIATED WITH INDIAN COALSPROBLEMS ASSOCIATED WITH INDIAN COALS

INCONSISTENT COAL PROPERTIESINCONSISTENT COAL PROPERTIESPRESENCE OF EXTRANEOUS MATTERS IN COALHIGH QUANTUM OF ASH WITH HIGH PERCENTAGE OF QUARTZHIGH QUANTUM OF ASH WITH HIGH PERCENTAGE OF QUARTZHIGHLY ABBRASIVE NATURE OF COAL ASHDUE TO LOW SULPHUR CONTENT- EXTREMLY HIGH ELECTRICAL RESISTIVITY OF ASHLOW HEATING VALUE OF THE COAL

FURNACE SELECTION CRITERIAFURNACE SELECTION CRITERIA

NHI / PANHI / PA

NHI / EPRS

Q FIRED / VOLUMEQ FIRED / VOLUME

BURNER ZONE HEAT RELEASE RATE

C S CFURNACE RESIDENCE TIME

DISTANCE BETWEEN FURNACE BOTTOM-HOPPER & LOWER MOST FUEL NOZZLE

DISTANCE BETWEEN UPPER MOST FUEL - NOZZLE & BOTTOM OF SH

FURNACE OUTLET TEMPERATURE

ASPECT RATIO

FURNACE HEAT LOADINGSFURNACE HEAT LOADINGS

» EPRS LOADING

» PLAN AREA LOADING

» VOLUMETRIC LOADING» VOLUMETRIC LOADING

» BURNER ZONE HEAT RELEASE RATE

PLAN AREA LOADINGS FOR BHEL BOILERSPLAN AREA LOADINGS FOR BHEL BOILERS

DESCRIPTION UNIT 67 5 MW 120 MW 210 MW 500 MWDESCRIPTION UNIT 67.5 MW 120 MW 210 MW 500 MW

NET HEAT INPUT 10 6

Kcal/h 189 319 542 12702

FURNACE PLAN AREA m2

62.4 78 147 276

FRING ZONE SURFACE m2

86.8 126.9 254.4 621.86 2

NHI / PA 10 6

Kcal/ m2

h 3.03 4.09 3.69 4.61

NHI / FZS 10 6

Kcal/ m2

h 2.18 2.51 2.13 2.04

VU40 RENUSAGAR 67.5MW

CESE CALCUTTA 67.5 MW

110 MW SABARMATHI

120 MW BOILER NALCO

Prai Thermal Power Station 3 x 120 MWStation 3 x 120 MW

Pasirgudang TPS 2 x 120 MW

Tripoli (W) TPS Tripoli (W) TPS 2 x 120 MW

200 MW NTPC KORBA200 MW NTPC KORBA

210 MW TNEB - TUTICORIN

210 MW APSEB VIJAYAWADA - 1

210 MW NTPC NCTP-DADRI

210 MW APSEB VIJAYAWADA-3TOWER TYPETOWER TYPE

210MW TOWER TYPE NEYVELI

CONTROLLED CIRCULATIONCONTROLLED CIRCULATIONSTEAM GENERATORS

500MW TROMBAY-5 BOILER

500 MW NTPC SINGRAULI 6

ONCE THROUGHONCE THROUGHSTEAM GENERATORS

Once -thru Boiler-Furnace Wall

500 MW TALCHER –NTPC500 MW TALCHER NTPC

(Sub critical once-through)through)

INDUSTRIALSTEAM GENERATORSSTEAM GENERATORS

BHEL Industrial Boilers

1 VP Vertical Package Boiler2 VU 60 Vertical Unit3 VU 40 Vertical Unit3 VU 40 Vertical Unit4 VU 40S Vertical Unit (Stoker)5 VU 60S Vertical Unit (Stoker)6 MU Modular Unit6 MU Modular Unit7 V2R Chemical Recovery2 y

Industrial Boilers - CapacityCType Capacity Max.Design Temperature

Pressuret / h k / 2( ) 0 Ct / h kg/cm2(g) 0 C

VP 10 250 125 515VP 10-250 125 515VU 60 60-450 125 540VU 40 100-480 125 540VU 40 100 480 125 540VU 40 S 50-125 125 500VU 60 S 30-70 125 485MU 80-350 125 540V2R 140-675(TPD) 125 4802

VP Boiler Design Features

Bi-Drum Bottom supported

Natural Circulation

Wall firing - Oil/Gas

Pressurised/Balanced Draft

Welded Furnace Wall

Single/Multi Pass Gas Flow across Boiler bank

Drainable Superheaters

Economiser and/or Airpreheater.

Minimum Refractory & Insulation

Wide steam temperature control range

Fast response to load swings

VU60 Boiler Design Features

Bi-Drum Bottom supported

Natural CirculationNatural Circulation

Front wall/Tangential Firing - Oil/Gas

Pressurised / Balanced DraftPressurised / Balanced Draft

Welded Furnace Wall

Multi-Pass Gas flow across Boiler BankMulti Pass Gas flow across Boiler Bank

Economiser and/or Airpreheater

Minimum Refractory & Insulationy

Wide steam temperature control range

Fast response to load swingsg

VU40 Boiler Design Features

Bi-Drum Top supported

Natural CirculationNatural Circulation

Tangential/Front wall Firing -Coal/Oil/Gas

Balanced Draft Welded Furnace wall

Single Pass Gas flow across Boiler Bank

Economiser and Airpreheater

Minimum Refractory & Insulation

Fast response to load swings

VU40 (Stoker) Boiler Design Features

Bi-Drum Top supported

Natural Circulation

Grate Firing - Coal/Lignite/Cellulose Fuels

Balanced Draft Welded Furnace wall

Single Pass Gas flow across Boiler Bank

Economiser and Airpreheater

Minimum Refractory & Insulation

Fast response to load swings

MU Boiler Design Featuresg

Single Drum Natural Circulation

Bottom or top supported

Fully welded construction

D i bl S h tDrainable Superheater

Integral Economiser

Pressurised/Balanced DraftPressurised/Balanced Draft

Wider control range

Minimum Refractory & InsulationMinimum Refractory & Insulation

Quick start-up

Less space requirementLess space requirement

V2R Recovery Boiler Design Features

Bi-Drum top supported

Natural Circulation

Balanced Draft

Welded Furnace Wall

Widely spaced Tangent tube SH

Single Pass Gas Flow across Boiler bank

Vertical straight Finned Economiser

Twin wheel cascade evaporator system or Large Economiser system.

Suspension firing system with multiple black liquor guns

Decanting hearth

O ti i d b ti i tOptimised combustion air system

HEA ignitors for starting burners

Minim m Refractor & Ins lationMinimum Refractory & Insulation

Additional QC checks for WW tubes

IMPLICATIONS OF HIGHER STAEM PAREMTERS ON IMPLICATIONS OF HIGHER STAEM PAREMTERS ON BOILER DESIGNBOILER DESIGN

BOILER TYPEMATERIALSMATERIALSRELIABILITY AND AVAILABILITY

NEED FOR PROPER MATERIAL SELECTIONNEED FOR PROPER MATERIAL SELECTION

PROPER SELECTION ENSURE SAFE - METAL TEMPERATURE UNDER ALL - OPERATING CONDITIONSPROPER SELECTION HELPS IN - - ---REDUCING THE INSTALLATION COST.

SELECTION OF AUXILIARIESSELECTION OF AUXILIARIES

AIRHEATERSAIRHEATERS

FANS

MILLS

ELECTROSTATIC PRECIPITATOR

AIRHEATER PERFORMANCE VARIATIONSAIRHEATER PERFORMANCE VARIATIONS

Fuel moistureFuel moisture

Airheater leakage

Airheater seals

Gas temperature leaving the airheaterp g

MILL PERFORMANCE VARIATIONSMILL PERFORMANCE VARIATIONS

MILL OUTLET / INLET TEMPERTURE

FUEL QUALITY LIKE MOISTURE / HGI / HHV

FAN PERFORMANCEFAN PERFORMANCEFAN PERFORMANCEFAN PERFORMANCE

LOADING OF FANS

POWER CONSUMPTION

ESP PERFORMANCE VARIATIONSESP PERFORMANCE VARIATIONS

DUE TO AIR HEATER LEAKAGE

DUE TO HIGHER GAS TEMPERATURE LEAVING AIR HEATERSDUE TO HIGHER GAS TEMPERATURE LEAVING AIR HEATERS

MAJOR VARIABLES AFFECTING THE BOILER MAJOR VARIABLES AFFECTING THE BOILER PERFORMANCEPERFORMANCEPERFORMANCEPERFORMANCE

EFFECT OF BOILER PARAMETERS

FUEL ANALYSIS VARIATIONSFUEL ANALYSIS VARIATIONS

VARIATIONS IN AUXILIARY

EQUIPMENT PERFORMANCE VIZ .,

MILLS, AH,FANS

OPERATING VARIABLES AFFECTING SLAGGINGOPERATING VARIABLES AFFECTING SLAGGING

EXCESS AIR

DISTRIBUTION OF AIR

DISTRIBUTION OF COALDISTRIBUTION OF COAL

FINENESS OF COAL

NUMBER OF OPERATING BURNER ELEVATIONS

FREQUENCY OF WALL BLOWER OPERATIONQ

LOADING OF BLOWER

OPERATING CONDITIONS AFFECTING THE OPERATING CONDITIONS AFFECTING THE PERFORMANCEPERFORMANCE

LOW PRESSURE OPERATION

HIGHER EXCESS AIR HIGHER EXCESS AIR

HP HEATER NOT IN SERVICE

GRID FLUCTUATIONS

FUEL QUALITY AFFECTING THE PERFORMANCEFUEL QUALITY AFFECTING THE PERFORMANCE

SLAGGING

FOT VARIATIONFOT VARIATION

SH / RH SPRAY VARIATION

FLUE GAS TEMPERATURE LEAVING BOILER

MILL LOADING

AUX .POWER CONSUMPTION

BOILER EFFICIENCY

USE OF INDIAN COALS DESIGN CONSIDERATIONSUSE OF INDIAN COALS DESIGN CONSIDERATIONSO SBOILERS:

CONSERVATIVE FURNACE HEAT LOADINGS

LOWER FLUE GAS VELOCITY OVER TUBE BANKS

PLAIN TUBE IN – LINE ARRANGEMENT OF HEAT TRANSFER SURFACE

-OPTIMUM END GAPS TO AVOID PREFERENTIAL GAS FLOW

-EROSION SHIELSA / CASSETTE BAFFLES

-EROSION ALLOWANCE FOR LEADING TUBES

-CAST STEEL PF BENDS & CERAMIC LINEDPF BENDS

*BOILER AUXILIARIES

-IMPROVED SEALING ARRANGEMENT IN AIRHEATERSIMPROVED SEALING ARRANGEMENT IN AIRHEATERS

-EXTENDED TUBE-TUBULAR APH

-LOW SPEED RADIAL ID FANS-LOW SPEED RADIAL ID FANS

-LINED IMPELLERS OF RADIAL FANS

R 4S 1

D R U M

STEAM & WATER CIRCUIT

R 2

R 3S 2

S 1

S 3S 4

S 5 S 5S 6S 1 7 S 1 7S 6

R 1

DESH

R 2S 6S 1 7

S 8

S 1 8

S 7S 9 S 1 1 S 1 1 S 9

S 7

S 1 8S 1 9

S 1 2S 2 0 S 2 0

S 1 4 S 1 4S 1 5 S 1 5

S 1 0

S 1 3 R H S Y S T E M

E 6E 7 E 7

S 1 6S 2 1

S 2 2S 2 3

L O W T E M P S H

S 2 4

E 4 E 4

E 5 E 5

E 6

S 2 6S 2 7

S 2 8 P L A T E N S HS 2 9

S25

E 2E 1

E 3 E 3

S 2 9

S 3 0

S 3 1

F IN A L S HS 3 2S 3 3

E C O S Y S T E MS H S Y S T E M

SCHEME OF AIR & GAS DUCTS / CIRCUITSCOLD PA SYSTEM

FURNACE SLAGGING INDICES

1 BASE / ACID RATIO1. BASE / ACID RATIO

Fe O + Cao + Mgo + Na O + K O (B)Fe2 O3 + Cao + Mgo + Na2O + K2O (B)

SiO2 + Al2O3 + Tio2 (A)2 2 3 2 ( )

Slagging potential:

B / A < 0.25 Low

0.25 - 0.40 Medium

0 40 0 70 Hi h0.40 - 0.70 High

(Eastern and Midwestern Bituminous Coals)( )

2.SULPHUR INDEXB

x S (% By weight in Fuel Dry Basis)B

A

< 0.6 Low

0.6 - 2.0 Medium

2.0 - 2.6 High

> 2.6 Servere

Bituminous if

Fe2 O3 > Cao + Mgo

3. IRON / CALCIUM RATIO

Fe2 O3 / CaO(OR)

Fe2 O3 / CaO + MgO (if MgO % is more)

0.3 – 3.0 High Slagging

HT + 4 IT

4.FUSION INDEX

Rs =5

HT=Hemi spherical temperature

IT =Initial Fusion Temperature

Rs:1230- 1340 Medium

1150- 1230 High

<1150 Severe

5.VISCOSITY / ASH FUSION TEMPERATURE

{T250 Poise (Oxid)–T10,000Poise(Red)}

RRs=

97.5 x fsMid Point fs

Temp. at 2000 Poise Value

2000 Deg. F 1.2

2200 2.0

2400 3 22400 3.2

2600 5.2

Rs < 0.5 Low

0.5 - 1.0 Medium

1.0 - 2.0 High

> 2.0 Servere

6.SILICA / ALUMINA RATIO6.SILICA / ALUMINA RATIO

SiO2SiO2

Al2 O3

< 1 7 Low< 1.7 Low

1.7 - 2.8 Medium

> - 2.8 High2.8 High

7.DOLOMITE PERCENTAGE

CaO + MgOCaO MgO

DP= x100

Fe2 O3 + CaO + MgO + Na2O + K2OFe2 O3 + CaO + MgO + Na2O + K2O

Coal with Basic Oxide > 40 %

Lower the DP Higher the Slagging Potential.

8.SODIUM OXIDE

Na2 O % By Weight of AshNa2 O % By Weight of Ash

< 1.0 Low

1.0 - 2.5 Medium

> - 2.5 High

Western Coals and Lignites

9.SODIUM AND POTASSIUM OXIDE9.SODIUM AND POTASSIUM OXIDE

Na2 O + K2 O % By Weight of AshNa2 O K2 O % By Weight of Ash

< 3.5 Low

3.5 - 5.0 Medium

> - 5.0 High

Western Coals and Lignites

10. IRON OXIDE

Fe2 O3 % By Weight of AshFe2 O3 % By Weight of Ash

< 12 Low

12 - 25 Medium

> - 25 High

Western Coals and Lignites

TOWER TYPE BOILERS ADVANTAGESTOWER TYPE BOILERS ADVANTAGESA TRULY SINGLE – PASS

ELIMINATES CHANGE IN DIRECTION OF GAS FLOW

MINIMISES EROSION OF PRESSURE PARTS.

INHERENTLY LOW GAS VELOCITY

DUE TO SH / RH SPACING

LESSER EROSION OF PRESSURE PARTSLESSER EROSION OF PRESSURE PARTS.

DRAINABLE SH ,RH SECTIONS

FASTER START UP AND SHUT DOWNSFASTER START-UP AND SHUT-DOWNS.

OCCUPIES LESS GROND SPACE.

ADOPTED THROUGHOUT EUROPE ADOPTED THROUGHOUT EUROPE

WELL ESTABLISHED DESIGN

TWO PASS Vs TOWER TYPE

G fl 2 1Gas flow passes 2 1

No. of turns 2 None

Gas velocity Base LowerGas velocity Base Lower

Erosion Potential Base Less

Height of Boiler Base + 30 %g

Weight of boiler Base + 5 % - 15 %

Erection` Multi f t

Single frontfront