01 - Boiler Performance & Design
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Transcript of 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