PAPERTECH 2010 SPB Presentation 5 June2010

8/8/2019 PAPERTECH 2010 SPB Presentation 5 June2010

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ADVANCESINPOWERENHANCEMENTINCOGENBATTERY

INSESHASAYEEPAPERMILL

DrT.G.Sundara Raman

Seshasayee Paper & Boards Ltd.

PAPER TECH 2010

CII

Hyderabad

16 June 20101


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InternationalpracticeinrunningSteamturbogenerator

[STG]battery

GENERAL

RunSTGofhighercycleefficiencyatincreasedloadsand

yetmeeting

the

process

steam

demands

OtherSTGsatlowerloadsthusactingasslave

ChemicalRecoveryBoiler[CRB]&CoalfiredBoiler[CFB]

Cogen units

RunCRB

Cogen with

black

liquor

solids

as

fuel

CFBCogen shallcaterto balanceload

2


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HPCOGENBATTERYINPREMIERPAPERMILLS

Mill CFB(kg/cm) CRB(kg/cm)

APPM 64 64

ITC 64 64

JK* 88/106 64/88

SPB 106 65

WCPM 64 64

TNPL

* : Planned

64 64

3


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Existing HPCogen Scenerio inSPB

CaptivePowerPlant[CPP1]

Boiler#10

[106

kg/cm /510C

AFBC

]&

21MWDoubleextractioncondensingsteamturbo

generator

CaptivePowerPlant[CPP2]

Boiler#11

[65

kg/cm /465C

CRB]

&

16MWExtractionbackpressuresteamturbogenerator

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SPECIFICATIONS OF THE 2 HP COGEN UNITSCPP Chem ic al Rec over y Cogen

Boiler #10 Parameter Boiler #11

AFBC Boiler Type Chemical Recovery Boiler

117 TPHRat ed St eam

Evaporat ion83TPH(Phase1) I140TPH(Phase2)

106 kg/cm SOP 65 kg/cm

510C SOT 465

C

135C Feed in le t t empera tur e 135C

Imported coalFuel

Black liquor

@ 70% solids concn.

21 MW- DEC STG 16 MW- EBP

10.5/4.0 kg/cm E1/E2 10.5/4.5 kg/cm

0.09 ata Condensing --

20.4 MW Capac i ty 10MW(Phase1) / 16 MW(Phase2)5


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Boiler#10 CFB&

Boiler#11 CRB

STEAMINGCONDITIONS

Parameter Blr #10 Blr #11

Fuel ImportedCoal BlackLiquorSolids

SteamEvaporation

TPH 117 80/130

[Ph1/Ph2]

SteamPressure(kg/cm2) 106 65

SteamTemperatureC 510 465

FeedWaterTemperatureC 135 135

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OPERATING LOADS

Boiler10operatingateconomic load(85%)withImported

coalas

fuel

Boiler11designedforPhase1(60%)&

Phase 2(100%)operationwithBlack

liquor solidsfiringinCRB

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TurbineExtractionExhaust SteamRange

ZONE 21MWSTG 16MWSTG

E1[MP] 030TPH 060TPH

E2[LP] 060TPH 30130TPH

Condensing 2550

TPH X

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ENERGYDISTRIBUTIONACROSS16MWSTG

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.

.

10

POST MDP [PHASE I] FLOW CHART

31 tph

22 tph

42 tph

Falling FilmEvaporator

8.7 MW

EB P16M W STG

73 tph

95 tph

DEC21M W STG

15.6 MW

0.1 MW

Weak Black Liquor fromPulp Mill

Strong BlackLiquor 70%

Concentration

Total Power : 24.4 MW

B#11 CRB65 kg/cm2

CW

65 tph

8 tph

586 tpd

AFBC#10106 kg/cm2

CPP/CFB

GRIDIMPORT

11 kg/cm2

Steam Header

To ProcessStation

Consumption

4 kg/cm2

Steam Header

To ProcessStationConsumption


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PHILOSOPHY

16MW

STG

is

designed

for

both

the

phases

of

operating

loads(60%to100%)

Henceextractionstage(nozzle)isdesignedbyBHELtocommensuratewithratedsteamingconditionsatthe

headerfor

Process(11

kg/cm2)

Obviouslyat

lower

loads

of

operation,

higher

turbine

nozzlesteamtemperaturesareunavoidable

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.

0

50

100

150

200

250

300

350

400

0 5 10 15 20 25 30 35 40 45

T

emp(Degc)

E1(TPH)

16MWSTGE1flowVsNozzle steamtemperature

Tnoz

Tsat


13/23

.

0

5

10

15

20

25

30

0 5 10 15 20 25 30 35 40 45

H(Kcal/Kg)

E1(TPH)

16MWSTGE1flowVsEnthalpydifferential


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.

0

50

100

150

200

250

0 20 40 60 80 100 120 140

Te

mp(DegC)

E2(TPH)

16MWSTGE2flowVsNozzlesteamtemperature

Tnoz

Tsat


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.

0

2

4

6

8

10

12

14

16

0 20 40 60 80 100 120 140

h(Kcal/Kg)

E2(TPH)

16MWSTGE2flowVsEnthalpydifferential


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AvailableEnergyforConversionfromThermal

16MWSteamturbogenerator

1.5MW

(th)

each

from

turbine

nozzles

of

both

E1

&

E2

upto saturationareavailable

Equivalent

to

15to

20

%

of

total

energy

through

reduction

ofsteamtemperaturethroughdesuperheating alone.

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17/23

RECOMMENDATIONS

Splitting E1(M.P.steamextraction)flowsbetweenthe2steamturbinestobeminimized.

EnsureentireE1flowthroughoneofthe2STGs

AccordinglysplitE2(L.P.steamextraction)flowbetweenthe 2steamturbines

Maximizecombinedcycleefficiencyinpowerwitheitherof

theturbines

acting

as

slave.

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POWERGENERATIONENHANCEMENTSCHEME[PES]ThroughshiftingofE1flowstooneSTG(insteadofsplittingofflows)

Extraction

Steam

flows

Actual

&

Potential

[TPH]1of2

SPB Actual Potential16MW 21MW 16MW 21MW

2010 E1 E1 E1 E2 E1 E2 C

March 13 15.7 28.7 41.8 0 53 37

April 13.7 14.9 28.6 45.6 0 49 38

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Powergenerationenhancement(estimated)

2of2

SPB

BothTG

inopern

E1

Addl.Power

estimated

E1S

reduction

estimated2010 hrs TPH MW Lakh

units

TPH TPM

March 694 28.7 0.31 2.2 0.44 300

April 636 28.6 0.31 2.0 0.43 275

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GainsfromPowerenhancementscheme

Higherelectricalpowergenerationwithloweringof

extraction(E1)steam

temperature

at

turbine

nozzle

Equivalent to 0.3MW onacontinuousbasis.

Reductionin

spray

quantity

required

for

desuperheating

ensuresbettersteamqualityforprocessuse.

XCounteracted

by

marginal

reduction

in

LP

steam

generation

throughdesuperheating

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ContributiontoPowerenhancementby

Energyefficientmainsteampipeline

Recommendedtogoinforhighlevelpipeline

insulation

for

a

design

temperature

drop

across

main

steamlineconnectingboilertosteamturbinefrom

8Cto 4C.

Throughtheaboveschemeinplace,powergenerationincrementof0.3MWshallbeensured

forthe

case

under

study

during

Phase

1operation.

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CONCLUSIONS&WAYFORWARD

Recommended for all Paper mills having HP Cogen Battery togo in for PES to suit process needs

Automation of the whole turbine energy cycle with

extraction flow limits in place is advocated

Temperature drop from Boiler main steam outlet to turbineinlet should be minimal (


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.

23

.

Conserve

Energy

Green the

Mother

Earth

Documents

PAPERTECH 2010 SPB Presentation 5 June2010