CenPEEPCenPEEP

USAID PACE-DHEAT RATE IMPROVEMENT PROGRAMMEHEAT RATE IMPROVEMENT PROGRAMME

AT CHANDRAPUR AND PANIPAT

T bi & A ili i P f A tT bi & A ili i P f A tTurbine & Auxiliaries Performance Assessment Turbine & Auxiliaries Performance Assessment

PMI NoidaPMI NoidaPMI, Noida19.09.2013PMI, Noida

19.09.2013

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HEAT RATE IMPROVEMENT PROGRAMME

Turbine & Auxiliaries Performance AssessmentTurbine & Auxiliaries Performance AssessmentTurbine & Auxiliaries Performance Assessment Turbine & Auxiliaries Performance Assessment 

ChandrapurChandrapur Unit Unit –– 6 (500 MW):6 (500 MW):44thth to 8to 8thth March, 2013March, 2013

P i tP i t U itU it 5 (210 MW)5 (210 MW)PanipatPanipat Unit Unit –– 5 (210 MW):5 (210 MW):1111thth to 15to 15thth March, 2013March, 2013

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Indian Coal Station

Impact of Efficiency

Indian Coal Station

1 kcal//kWh Coal Saving 2,37,091 Tons

CO2 Reduction 2,95,655 Tons

Cost Reduction Rs. 56.9 Crores

All data on annual basis

67 kcal//kWh1 % Eff Coal Saving CO2 Reduction

Installed Capacity 1,18,409 MW, GCV 3500 kcal/kg , Coal Cost Rs 2400 per Ton, PLF 80%, FC 34%

Cost Reduction67 kcal//kWh Improvement

1 % Eff. Improvement

Coal Saving158,85,097 Tons

CO2 Reduction 198,08,885 Tons

Cost Reduction Rs. 3813 Crores

Same as above, Heat rate 2350 kcal/kWh

Per day Coal Consumption 6,240 Tons

500 MW Unit Annual Coal Consumption

22,77,600 Tons

Annual Coal Cost Rs. 318.84

Crores

Annual CO2 Production

28,47,000 Tons

S b S ifi l i 0 65 k /kWhSame as above, Specific coal consumption 0.65 kg/kWh

5 kcal//kWh Improvement

500 MW Unit Coal Saving 5,008 Tons

CO2 Reduction 6,261 Tons

Cost Reduction Rs. 1.2 Crores

S bSame as above

CenPEEPCenPEEPMajor Heat Rate Loss Areas

Typical Major Heat Rate Loss Area

Dry FG Loss, 22%

Unaccountable, 21% 

RH S 9%

Cooling Tower, 8% RH Spray, 9%8%

HPT Eff, 12%IPT Eff, 10%

Condenser Loss, 18%

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Turbine & Auxiliaries Performance Test

Performance test Carried Out:

Turbine & Auxiliaries Performance Test

• Gross Turbine Cycle Heat rate (GTCHR )• HP & IP Turbine Cylinder Efficiency  Condenser Performance• Condenser Performance 

• HPH performance • FW Flow validation• Cooling Tower Walk Down Survey• Cooling Tower Walk Down Survey

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Gross Turbine Cycle Heat RateyTurbine Cycle Heat rate depends upon, how much heat is 

utilized for generation of one unitg

GTCHR = Heat added in the cycle / Total MW generated

• Major components affecting the Turbine Cycle ffEfficiency are

HP / IP /LP Turbine CondenserHP HeatersImproper Cycle Isolation (Unaccountable Losses)Improper Cycle Isolation (Unaccountable Losses)RH Spray

CenPEEPCenPEEPGross Turbine Cycle Heat Rate

Performance Test Code: ASME PTC 6S

CenPEEPCenPEEPGross Turbine Cycle Heat Rate

Gross Load Gross Load MWMW FW Press HPH InletFW Press HPH Inlet Kg/cm2(abs)Kg/cm2(abs)

MS Pressure before ESVMS Pressure before ESV Kg/cm2(abs)Kg/cm2(abs) FW Temp HPH InletFW Temp HPH Inlet Deg.CDeg.CMS Temp before ESVMS Temp before ESV Deg.CDeg.C FW Press HPH OutletFW Press HPH Outlet Kg/cm2(abs)Kg/cm2(abs)

HPT Exhaust PressureHPT Exhaust Pressure Kg/cm2(abs)Kg/cm2(abs) FW Temp HPH OutletFW Temp HPH Outlet Deg.CDeg.C

HPT E h t T tHPT E h t T t D CD C M i St FlM i St Fl T/hT/hHPT Exhaust TemperatureHPT Exhaust Temperature Deg.CDeg.C Main Steam Flow Main Steam Flow (Q1)(Q1)

T/hrT/hr

HRH Steam Pressure before HRH Steam Pressure before IVIV

Kg/cm2(abs)Kg/cm2(abs) Feed Water Flow (Qf)Feed Water Flow (Qf) T/hrT/hr

HRH Steam Temp. before IVHRH Steam Temp. before IV Deg.CDeg.C CRH Flow (Q2)CRH Flow (Q2) T/hrT/hr

FW press after top heaterFW press after top heater Kg/cm2(abs)Kg/cm2(abs) S/H Spray Flow (Qs)S/H Spray Flow (Qs) T/hrT/hr

FW T t E i l tFW T t E i l t D CD C R/H S Fl (Q )R/H S Fl (Q ) T/hT/hFW Temp at Eco inletFW Temp at Eco inlet Deg.CDeg.C R/H Spray Flow (Qr)R/H Spray Flow (Qr) T/hrT/hr

HPH Ext. Steam TempHPH Ext. Steam Temp Deg.CDeg.C S/H Spray S/H Spray TemperatureTemperature

Deg.CDeg.C

HPH Shell PressureHPH Shell Pressure Kg/cm2(abs)Kg/cm2(abs) R/H SprayR/H Spray Deg CDeg CHPH Shell PressureHPH Shell Pressure Kg/cm2(abs)Kg/cm2(abs) R/H Spray R/H Spray TemperatureTemperature

Deg.CDeg.C

HPH Drip TempHPH Drip Temp Deg.CDeg.C Leak Off FlowLeak Off Flow T/hrT/hr

CenPEEPCenPEEPTurbine & Auxiliaries Performance Test

• GTCHR test was carried out on for one hour at VWO condition. • Control room parameters from DAS were averaged during the test

duration. • Online measurements of some of the Critical Parameters were

• GTCHR test was carried out on for one hour at VWO condition. • Control room parameters from DAS were averaged during the test

duration. • Online measurements of some of the Critical Parameters were• Online measurements of some of the Critical Parameters were

validated using offline instruments. • Online measurements of some of the Critical Parameters were

validated using offline instruments.

Chandrapur Unit – 6: Load Maintained at 480 MW Chandrapur Unit – 6: Load Maintained at 480 MW

• The Gross turbine Cycle Heat Rate (GTCHR) as per test data was 2026kcal/kWh and test corrected GTCHR value of 2033 kcal/kWh(corrected for CW inlet Temp of 28.7 0C/ Design 30 0C) at 480 MW as

• The Gross turbine Cycle Heat Rate (GTCHR) as per test data was 2026kcal/kWh and test corrected GTCHR value of 2033 kcal/kWh(corrected for CW inlet Temp of 28.7 0C/ Design 30 0C) at 480 MW as(co ected o C et e p o 8 C/ es g 30 C) at 80 asagainst design of 1965 Kcal/kWh (at VWO condition) there by havinga HR deviation of 68 kcal/kWh.

(co ected o C et e p o 8 C/ es g 30 C) at 80 asagainst design of 1965 Kcal/kWh (at VWO condition) there by havinga HR deviation of 68 kcal/kWh.

Panipat Unit 5: Load Maintained at 211 MWPanipat Unit – 5: Load Maintained at 211 MW

• The Gross turbine Cycle Heat Rate (GTCHR) as per test data was 2106kcal/kWh and test corrected GTCHR value of 2126 kcal/kWh(corrected for CW inlet Temp of 29.1 0C/Design 32 0C) at 211 MW asagainst design of 1983 Kcal/kWh (at VWO condition) there by havinga HR deviation of 143 kcal/kWh.

CenPEEPCenPEEPGTCHR Test : Chandrapur Unit – 6 (Unit Load : 480 MW)

Sl No. Description Heat Rate (Kcal / Kwh)

1 Test GTCHR (VWO) 2026

2 Test Corrected GTCHR (Corrected for CW I/L 20332 Test Corrected GTCHR (Corrected for CW I/Ltemp of 28.7°C / D‐30°C)

2033

3 Design GTCHR (VWO) 1965

4 Total Deviation in GTCHR 68

5 Condenser loss due to CW flow / Heat load 13

6 Condenser loss due to dirty tube / air ingress 27

7 HP Turbine Efficiency (83.1% / D ‐ 88.76%) 167 HP Turbine Efficiency (83.1% / D   88.76%) 16

8 IP Turbine Efficiency (91.37% / D – 91.41%) ‐

9 FW temp of Eco Inlet (252.87°C/ D ‐255.7°C) 3

10 MS Temperature (547 3°C/ D ‐537°C) ‐10

D - Design

10 MS Temperature (547.3 C/ D  537 C) 10

11 MS Pressure (165.2 Ksc / D ‐170 Ksc) 3

13 HRH Temperature (543.5°C/ D ‐537°C) ‐3

14 RH Spray flow (42 t/hr) 1014 RH Spray flow (42 t/hr) 10

15 Total accountable losses 59

16 Unaccountable losses 9

CenPEEPCenPEEPGTCHR Test : Panipat Unit – 5 (Unit Load : 211 MW)

Sl No. Description Heat Rate (Kcal / Kwh)

1 Test GTCHR (VWO) 2106

2 Test Corrected GTCHR (Corrected for CW I/Lt f 29 1°C / D 32°C)

2126temp of 29.1°C / D‐32°C)

3 Design GTCHR (VWO) 1983

4 Total Deviation in GTCHR 143

/5 Condenser loss due to CW flow / Heat load 8

6 Condenser loss due to dirty tube / air ingress 44

7 HP Turbine Efficiency (81.1% / D ‐ 87%) 18

8 IP Turbine Efficiency (86.06% / D – 90.51%) 14

9 FW temp of Eco Inlet (240°C/ D ‐240.5°C) ‐

10 MS Temperature (537.5°C/ D ‐535°C) ‐2

D - Design

11 MS Pressure (141.6 Ksc / D ‐150 Ksc) 9

13 HRH Temperature (524.5°C/ D ‐535°C) 5

14 RH Spray flow (13.5 t/hr) 4

15 Make Up Flow (7 t/hr) 20

16 Total accountable losses 120

17 Unaccountable losses 23

CenPEEPCenPEEPFW Water Flow Validation at Panipat Unit - 5

• Unit - 5 FW Flow measurements was carried out using hightemperature ultrasonic flow meter at the HPH – 5 inlet line.

• The Flow measured using ultrasonic flow meter was showing680.5 t/hr as against the online flow value on the same line of700 t/hr.

• 20 t/hr in FW Flow measurement corresponds to GTCHR of 60kcal/kWh (for typical 210 MW Unit).

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Impact of Turbine Efficiency on HR/Output

Description Effect on Effect on

Impact of Turbine Efficiency on HR/Output

pTG HR KW

1% HPT Efficiency 0 16% 0 3%1% HPT Efficiency 0.16% 0.3% (app 3 kcal)

1% IPT Efficiency 0.16% 0.16%( )(app 3 kcal)

1% LPT Efficiency 0.5% 0.5%(app 10 kcal)Impact of Turbine Efficiency on HR/Output ( pp )

Output Sharing by Turbine CylindersHPT 28%

p y pneeds to be calculated on Unit specific basis

IPT 23%LPT 49%

CenPEEPCenPEEPTurbine Efficiency Measurements

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Turbine Isentropic Efficiency

Used EnergyTurbine Isentropic Efficiency =

Available Energy

hin - hout=

h hMajor Issues: hin – hisen

Whereh = Enthalpy at Cylinder Inlet conditions

Major Issues:

• Turbine Efficiency Test to be carried out at VWO Condition• Turbine Offline Testing to be carried out twice in a year & pre-post COHhin = Enthalpy at Cylinder Inlet conditions

hout = Enthalpy at Cylinder Outlet conditionshisen = Isentropic Enthalpy

• Turbine Offline Testing to be carried out twice in a year & pre post COH• Retention of PG Test Points for new units• Water leg correction to be incorporated in online pressure measurements• Calibration/upkeep of offline instrumentsp p

CenPEEPCenPEEPTurbine Efficiency Gap

Breakup Of Turbine Efficiency Losses (%)

Leakage Loss - 50%

Surface Roughness - 36%

Others - 14%

CenPEEPCenPEEPTurbine Seals Loss break up

OTHERS SHAFT OTHERS6% SEALS

15%INTER

STAGE27%

TIP SEALSSEALS52%

CenPEEPCenPEEPSeal Leakage

DIAPHRAGM

TIPSPILL STRIPS

TIPLEAKAGE

TENON

STEAM FLOW

ROOT

ROTATINGBLADE

STATIONARYBLADESTAGE

PRESSURE

ROOT LEAKAGE

COVER ORSHROUD

Impulse Wheel andSPILL STRIPSDOVETAIL

Impulse Wheel and Diaphragm

Construction

BALANCE HOLE

WHEELPACKING

INTERSTAGE PACKING LEAKAGE

BALANCE HOLEFLOW

SHAFT

INTERSTAGE PACKING LEAKAGE

CenPEEPCenPEEPSeal Leakage

BLADECARRIER

TIP SPILLSTRIPS TENONTIP

LEAKAGECOVER

STATIONARYBLADE

ROTATINGBLADE

TRAILINGEDGE

LEADINGEDGE

Reaction Drum Rotor Construction

INTERSTAGEPACKING

ROTOR

CenPEEPCenPEEPTurbine Surface Roughness

• Surface finish degradation:

- Deposits

Corrosion- Corrosion

- Solid Particle Erosion

- Mechanical damage

• Roughness up to 0.05 mm can lead to decrease in efficiency by 4%

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Solid Particle Erosion

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h lMechanical Damage

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Bl d D itBlade Deposits

CenPEEPCenPEEPTurbine Seal DamageTurbine Seal Damage

MISSING SEAL STRIPSMISSING SEAL STRIPS

Tip seal strips : missing, slots washed out

CenPEEPCenPEEPHP/IP Turbine – Chandrapur Unit - 6

• The HP Turbine Efficiency test was carried out in VWO condition.The HPT efficiency as per test data is 83.1 % as against design value(VWO) of 88.76 %.There is a deterioration of about 5 66 % in HPT efficiency This

• The HP Turbine Efficiency test was carried out in VWO condition.The HPT efficiency as per test data is 83.1 % as against design value(VWO) of 88.76 %.There is a deterioration of about 5 66 % in HPT efficiency This• There is a deterioration of about 5.66 % in HPT efficiency. Thiscorresponds to a HR loss of 16 Kcal/kWh.

• There is a deterioration of about 5.66 % in HPT efficiency. Thiscorresponds to a HR loss of 16 Kcal/kWh.

Description HPT Exhaust Pressure Throttle Pressure HPT Exh. / Throttle Pr.pKg/cm2( a) Kg/cm2( a)

/

HBD 47.02 170 0.2766

Test Data 48.8 165.2 0.2953

The increase in pressure ratio indicates increase in turbine clearances.• It is suggested that the gland seal / inter‐stage seal strips condition as well

it l b h k d t th t il bl t it

The increase in pressure ratio indicates increase in turbine clearances.• It is suggested that the gland seal / inter‐stage seal strips condition as well

it l b h k d t th t il bl t it

• The IPT efficiency as per test data is 91.37 % as againstdesign value (VWO) of 91.41 %.

• There is a no deterioration in IPT efficiency.as its clearances may be checked at the next available opportunity.• It is proposed to trend the HPT efficiency at VWO (to track the degradation).

• It is suggested that the pressure ratio of HPT exhaust to throttle pressure

as its clearances may be checked at the next available opportunity.• It is proposed to trend the HPT efficiency at VWO (to track the degradation).

• It is suggested that the pressure ratio of HPT exhaust to throttle pressure

y

It is proposed to trend the Efficiency at VWO (to track the degradation)It is proposed to trend the Efficiency at VWO (to track the degradation)

gg p pshould also be monitored, trended and analyzed for correlating with changein Turbine clearances/deposits.

gg p pshould also be monitored, trended and analyzed for correlating with changein Turbine clearances/deposits.

CenPEEPCenPEEPHP Turbine – Panipat Unit - 5

• The HP Turbine Efficiency test was carried out in VWO condition.The HPT efficiency as per test data is 81.1 % as against design value(VWO) of 87 %.There is a deterioration of about 5 9 % in HPT efficiency This

• The HP Turbine Efficiency test was carried out in VWO condition.The HPT efficiency as per test data is 81.1 % as against design value(VWO) of 87 %.There is a deterioration of about 5 9 % in HPT efficiency This• There is a deterioration of about 5.9 % in HPT efficiency. Thiscorresponds to a HR loss of 18 Kcal/kWh.

• There is a deterioration of about 5.9 % in HPT efficiency. Thiscorresponds to a HR loss of 18 Kcal/kWh.

Description HPT Exhaust Pressure Throttle Pressure HPT Exh. / Throttle Pr.pKg/cm2( a) Kg/cm2( a)

/

HBD 40.36 150 0.2690

Test Data 37.9 141.6 0.2676

The decrease in pressure ratio indicates of deposits in HP turbine. • It is suggested to check for deposits in HP Turbine at the next

il bl t it

The decrease in pressure ratio indicates of deposits in HP turbine. • It is suggested to check for deposits in HP Turbine at the next

il bl t itavailable opportunity.• It is proposed to trend the HPT efficiency at VWO (to track thedegradation). • It is suggested that the pressure ratio of HPT exhaust to throttle

available opportunity.• It is proposed to trend the HPT efficiency at VWO (to track thedegradation). • It is suggested that the pressure ratio of HPT exhaust to throttlegg ppressure should also be monitored and analyzed for change inTurbine conditions

gg ppressure should also be monitored and analyzed for change inTurbine conditions

CenPEEPCenPEEPIP Turbine – Panipat Unit - 5

• The IPT efficiency as per test data is 86.06 % as against design value(VWO) of 90.51 %.

• There is a deterioration of about 4.5 % in HPT efficiency. This

• The IPT efficiency as per test data is 86.06 % as against design value(VWO) of 90.51 %.

• There is a deterioration of about 4.5 % in HPT efficiency. Thisycorresponds to a HR loss of 14 Kcal/kWh.

ycorresponds to a HR loss of 14 Kcal/kWh.

Description IPT Exhaust PressureKg/cm2( a)

IPT Inlet PressureKg/cm2( a)

IPT Exh. / IPT Inlet Pr.g/ ( ) g/ ( )

HBD 7.07 34.31 0.2060

Test Data 7.64 34.7 0.2202

The increase in pressure ratio indicates the increase in turbine clearances. • It is suggested that the gland seal / inter-stage seal strips condition

ll it l b h k d t th t il bl

The increase in pressure ratio indicates the increase in turbine clearances. • It is suggested that the gland seal / inter-stage seal strips condition

ll it l b h k d t th t il blas well as its clearances may be checked at the next availableopportunity.

• It is suggested to provide online measurement of IPT Exhaustpressure and temperature which is presently not available.

as well as its clearances may be checked at the next availableopportunity.

• It is suggested to provide online measurement of IPT Exhaustpressure and temperature which is presently not available.p p p y

• It is suggested that the pressure ratio of IPT exhaust to IPT inletshould also be monitored and analyzed for change in Turbine clearances.

p p p y• It is suggested that the pressure ratio of IPT exhaust to IPT inlet

should also be monitored and analyzed for change in Turbine clearances.

CenPEEPCenPEEPCondenser Performance Monitoring

Parameters to be Monitored

• Condenser Back Pressure

• CW Inlet TemperatureCW Inlet Temperature

• CW Outlet Temperature

• Condensate temperature

• Air-steam mixture temperature

• Water box differential pressurep

• CW flow (Using Pitot Tube)

CenPEEPCenPEEP

NON-CONDENSABLE

Condenser Performance MonitoringNON-CONDENSABLE

OUTLETSTEAM INLET

NON-COND. REMOVAL SYSTEM

FT

P

AIR/VAPOR OUTLET

CW Inlet Temp : 2CW Outlet Temp : 8Condensate Temp: 2

PPP

OUTLET

WW

Condensate Temp: 2Back Pressure: 2CW Waterbox dP: 2 Air/steam Mixture

TWCONDENSATE LEVEL

P

Temp: 2

IRC

UL

AT

ING

A

TE

R O

UT

LE

T

CIR

CU

LA

TIN

G

WA

TE

R IN

LE

T

P

T

DO S

CONDENSATE

(Δ P)(Δ P)

P

CI

WA C W

F

T

F = FLOW MEASUREMENTW = WATER LEVEL MEASUREMENTP = PRESSURE MEASUREMENT

PERF. TEST CONNECTION

SUPPLEMENTAL TEST CONNECTION

T = TEMPERATURE MEASUREMENTDO = DISSOLVED OXYGEN MEASUREMENTS = SALINITY MEASUREMENT

CONDENSATE LEVEL

4 Nos.

TYPICAL CONDENSER INSTRUMENTATIONTYPICAL CONDENSER INSTRUMENTATION

P PRESSURE MEASUREMENT S SALINITY MEASUREMENT

CenPEEPCenPEEPTypical Condenser Calculations

S.NS.N ParameterParameter UnitUnit TestTest

Measured ParametersMeasured Parameters

LoadLoad MWMW PP 21021011 Condenser Pressure Condenser Pressure mm Hgmm Hg PcPc 120.8120.822 CW In TempCW In Temp Deg CDeg C TiTi 34 1634 1622 CW In Temp CW In Temp Deg.CDeg.C TiTi 34.1634.1633 CW Out Temp CW Out Temp Deg.CDeg.C ToTo 45.0945.0944 Condensate Condensate

TemperatureTemperatureDeg.CDeg.C TconTcon 5555

TemperatureTemperature55 Air suction TempAir suction Temp Deg.CDeg.C TaTa 48.9/50.0448.9/50.04

Calculated ParametersCalculated Parameters

66 Saturation TempSaturation Temp Deg.CDeg.C TsatTsat 55.5655.56

77 Expected Back Pressure * Expected Back Pressure * mm Hgmm Hg PxpPxp 8585

* Expected BP to be derived from design BP after applying corrections for Load

and CW inlet temperature during test

CenPEEPCenPEEPTypical Condenser Calculations

S.NS.N ParameterParameter UnitUnit TestTest

88 Design CW Temp RiseDesign CW Temp Rise Deg CDeg C dTdT 101088 Design CW Temp RiseDesign CW Temp Rise Deg.CDeg.C dTdT 1010

99 Design TTDDesign TTD Deg.CDeg.C TTDTTD 2.52.5

1010 Back Pressure due to CW InletBack Pressure due to CW Inlet mm Hgmm Hg Ti+dT+TTDTi+dT+TTD 7979Back Pressure due to CW Inlet Back Pressure due to CW Inlet Temperature Temperature

mm Hgmm Hg Ti dT TTDTi dT TTD 7979

1111 Back Pressure due to CW Flow Back Pressure due to CW Flow mm Hgmm Hg To+TTDTo+TTD 8181

1212 Variation due to CW Inlet Variation due to CW Inlet TemperatureTemperature

mm Hgmm Hg 77--1010 --66

1313 V i ti d t CWV i ti d t CW HH 1111 1010 221313 Variation due to CW Variation due to CW Flow/Heat LoadFlow/Heat Load

mm Hgmm Hg 1111--1010 22

1414 Variation due to air/Dirty Variation due to air/Dirty TubesTubes

mm Hgmm Hg 11--1111 39.839.8TubesTubes

1515 Total variation Total variation mm Hgmm Hg 11--1010 41.841.8

CenPEEPCenPEEP

Condenser Performance MonitoringFactors affecting Condenser BP deviation

T b f li

Co de se e o a ce o to g

• Tube foulingDeposits in tubesMonitor the Waterbox dp

• Air ingress into the systemMonitoring sub cooling of the air steam mixtureAir flow measurementAir flow measurement

• High Condenser heat loadImproper Cycle isolationImproper Cycle isolationHigh MS flow

• Boundary ConditionsBoundary ConditionsCW Inlet temperatureCW Flow

CenPEEPCenPEEPCondenser : Corrective Actions

Fouling: Soft deposits –

1. On Line Tube Cleaning (OLTC)(OLTC)

2. Back washingHard deposits: opportunity l i b

Major Issues:

cleaning by1. High pressure jet2. Hydro-powered Mech

scrappers (CONCO)

• Absolute Pressure measurement for condenser back pressure• Retention of PG Test Points for new units• Trending of Condenser performance parameters

scrappers (CONCO)3. Chemical cleaning

Pro-active action: water treatment of cooling water

• Availability of OLTC• Proper Chemical Treatment• Identification of Air-in-gress Points

Opportunity cleaningAppropriate maintenance for air-in-leak reductionAppropriate maintenance of cooling towerTube leak: tube plugging & replacement

• Opportunity cleaning• Operational optimisation based on calculation

Tube leak: tube plugging & replacement Proper operationProper cycle isolation

CenPEEPCenPEEPCondenser : Use of Multiple Technology

H l i th CRH t i d i liHole in the CRH strainer drain line Hole fixed up using clamp

Temperature difference taken by the IRT Camera around the hole

Benefits of Testing:1. Improvement in condenser vacuum by 16 mm Hg2 Stoppage of one vacuum pump there by reducing in APC

Temperature difference taken by the IRT Camera around the hole

2. Stoppage of one vacuum pump there by reducing in APC and increased operational reliability

3. Unit Heat rate improvement : 32 Kcal / KWHr

CenPEEPCenPEEP

At 480 MW d i ti i C d b k f t dAt 480 MW d i ti i C d b k f t d

Condenser – Chandrapur Unit - 6• At 480 MW, deviation in Condenser back pressure from expected

value, after necessary corrections was around 31 mm Hg• 10 mm Hg is on account of CW flow/heat load and 21 mm Hg is on

account of dirty tube / air ingress loss. It corresponds to a loss in

• At 480 MW, deviation in Condenser back pressure from expectedvalue, after necessary corrections was around 31 mm Hg

• 10 mm Hg is on account of CW flow/heat load and 21 mm Hg is onaccount of dirty tube / air ingress loss. It corresponds to a loss iny g pHeat Rate of about 40 kcal/ kWh

y g pHeat Rate of about 40 kcal/ kWh

Air-ingress & High Heat Load Losses

• The air suction depression was found to be 4.6 deg C which is slightlyhigher than design value (3.5 deg C).

• Two vacuum pumps are in service with air flow of 68 & 28 kg/hrti l

• The air suction depression was found to be 4.6 deg C which is slightlyhigher than design value (3.5 deg C).

• Two vacuum pumps are in service with air flow of 68 & 28 kg/hrti lrespectively.

• The two high energy drain valves found passing (MS line strainer drainvalve before ESV – 2 & Drain before HPCV – 4)

respectively.• The two high energy drain valves found passing (MS line strainer drain

valve before ESV – 2 & Drain before HPCV – 4)

• It is suggested to stop one vacuum pump and observe the condenser back pressure to confirm any air‐ingress in condenser.

• In case of air‐ingress, IRT , Acoustic and Helium leak detection test

• It is suggested to stop one vacuum pump and observe the condenser back pressure to confirm any air‐ingress in condenser.

• In case of air‐ingress, IRT , Acoustic and Helium leak detection testmay be used to identify air‐ingress location.

• It is suggested to provide thermocouples at the down streams location of high energy drain valves for online monitoring of valve passing if any.

may be used to identify air‐ingress location.• It is suggested to provide thermocouples at the down streams location

of high energy drain valves for online monitoring of valve passing if any.

CenPEEPCenPEEPCondenser – Chandrapur Unit - 6

• High solid deposits in condenser tubes. High dissolved solids• High solid deposits in condenser tubes. High dissolved solids

Dirty Tube & CW Flow Losses

g p gand slush observed in Cooling Water due to ash ingress fromnearby Silos

• The Condenser water box dp was 0.88 & 0.76 ksc which is

g p gand slush observed in Cooling Water due to ash ingress fromnearby Silos

• The Condenser water box dp was 0.88 & 0.76 ksc which ishigh as compared to design value of < 0.6 ksc indicatingchoking in condenser tubeshigh as compared to design value of < 0.6 ksc indicatingchoking in condenser tubes

• It is suggested to clean the condenser tubes duringopportunity (deposits need to be analysed) and optimize thechemical dozing in CW system to avoid hard deposits

• It is suggested to clean the condenser tubes duringopportunity (deposits need to be analysed) and optimize thechemical dozing in CW system to avoid hard deposits

• It is suggested to revive the operation of condenser online tubecleaning system (COLTCS) after hard deposits are removedfrom condenserI i l d dd b d

• It is suggested to revive the operation of condenser online tubecleaning system (COLTCS) after hard deposits are removedfrom condenserI i l d dd b d• It is also suggested to carry out eddy current tubes andreplacement of tubes as per recommendation

• It is also suggested to carry out eddy current tubes andreplacement of tubes as per recommendation

CenPEEPCenPEEP

Condenser – Panipat Unit - 5

• At 211 MW, deviation in Condenser back pressure fromexpected value after necessary corrections was around 26

p

expected value, after necessary corrections was around 26mm Hg

• 4 mm Hg is on account of CW flow/heat load and 22 mm Hg is4 mm Hg is on account of CW flow/heat load and 22 mm Hg ison account of dirty tube / air ingress loss. It corresponds to aloss in Heat Rate of about 52 kcal/ kWh

• High dirty tube losses due to deposits in condenser tubes

• The Condenser water box dp was 0.83 & 0.81 ksc which ishigh as compared to design value of < 0.6 ksc indicatingchoking in condenser tubes

High Make p ma be d e to blo do n operation from boiler• High Make up may be due to blow down operation from boiler.

CenPEEPCenPEEPCondenser – Panipat Unit - 5

• It is suggested to clean the condenser tubes duringopportunity and optimize the chemical dozing in CW system toavoid hard deposits

• It is suggested to clean the condenser tubes duringopportunity and optimize the chemical dozing in CW system toavoid hard deposits

• It is suggested to revive the operation of condenser online tubecleaning system (COLTCS) after hard deposits are removedf d

• It is suggested to revive the operation of condenser online tubecleaning system (COLTCS) after hard deposits are removedf dfrom condenser

• It is also suggested to carry out replacement of tubes as perrecommendation of eddy current test and hard deposits

from condenser

• It is also suggested to carry out replacement of tubes as perrecommendation of eddy current test and hard depositsrecommendation of eddy current test and hard deposits.

• It is suggested to keep one ejector in service (which wasdemonstrated during test period)

recommendation of eddy current test and hard deposits.

• It is suggested to keep one ejector in service (which wasdemonstrated during test period)demonstrated during test period)

• The weekly changeover schedule to be practiced to ensure thereliability of the standby ejector

demonstrated during test period)

• The weekly changeover schedule to be practiced to ensure thereliability of the standby ejectory y j

• It is suggested to provide online cation conductivitymeasurement at condensate line

y y j

• It is suggested to provide online cation conductivitymeasurement at condensate line

CenPEEPCenPEEPHP Heater – Chandrapur Unit - 6

• The Temperature rise across HPH – 5A/5B is 39.9/40.1 deg C asagainst design value of 45.1 deg C. There is shortfall in

• The Temperature rise across HPH – 5A/5B is 39.9/40.1 deg C asagainst design value of 45.1 deg C. There is shortfall intemperature rise in HPH 5A/5B by 5 deg C.

• It is observed that DCA of HPH 5A/5B are maintaining 13/12.7 degC i t d i l f 7 d C It i t d t ti i

temperature rise in HPH 5A/5B by 5 deg C.

• It is observed that DCA of HPH 5A/5B are maintaining 13/12.7 degC i t d i l f 7 d C It i t d t ti iC against design value of 7 deg C. It is suggested to optimizeheater level to improve the performance of HPH – 5A/5B.C against design value of 7 deg C. It is suggested to optimizeheater level to improve the performance of HPH – 5A/5B.

• The Temperature rises across HPH – 6A/6B are 44.1/45.4 deg C asagainst design value of 44.3 deg C. There is no shortfall intemperature rise in HPH 6A/6B.

• The Temperature rises across HPH – 6A/6B are 44.1/45.4 deg C asagainst design value of 44.3 deg C. There is no shortfall intemperature rise in HPH 6A/6B.temperature rise in HPH 6A/6B.

• The Final Feed water temperature after HPH‐6 was around 252.87deg C as against the design value of 255.7 deg C. Thus there is

temperature rise in HPH 6A/6B.

• The Final Feed water temperature after HPH‐6 was around 252.87deg C as against the design value of 255.7 deg C. Thus there isg g g gshortfall of around 3 deg C on Final Feed water temperature.

g g g gshortfall of around 3 deg C on Final Feed water temperature.

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• The Temperature rise across HPH 5 is 27 deg C as against• The Temperature rise across HPH 5 is 27 deg C as against

HP Heater – Panipat Unit - 5• The Temperature rise across HPH – 5 is 27 deg C as against

design value of 33 deg C. There is shortfall in temperature rise inHPH 5 by 6 deg C

• The Temperature rise across HPH – 5 is 27 deg C as againstdesign value of 33 deg C. There is shortfall in temperature rise inHPH 5 by 6 deg C

• It is observed that HPH – 5 TTD / DCA are maintaining 13.4/26.0deg C as against design value of 2.9/6.9 deg C

• It is observed that HPH – 5 TTD / DCA are maintaining 13.4/26.0deg C as against design value of 2.9/6.9 deg C

• It is suggested to inspect the HPH – 5 for any parting plate/ bypassvalve passing during opportunity and to optimize heater level toimprove the performance of HPH – 5

• It is suggested to inspect the HPH – 5 for any parting plate/ bypassvalve passing during opportunity and to optimize heater level toimprove the performance of HPH – 5

• The Temperature rises across HPH – 6 are 49 deg C asagainst design value of 43 deg C. There is no shortfall in

• The Temperature rises across HPH – 6 are 49 deg C asagainst design value of 43 deg C. There is no shortfall ing g gtemperature rise in HPH 6

• The Final Feed water temperature after HPH-6 was around 240

g g gtemperature rise in HPH 6

• The Final Feed water temperature after HPH-6 was around 240deg C as against the design value of 240.5 deg Cdeg C as against the design value of 240.5 deg C

CenPEEPCenPEEPCritical Parameters – Turbine Performance

A list of critical parameters that need to be cross checked for accuracyA list of critical parameters that need to be cross checked for accuracyA list of critical parameters that need to be cross checked for accuracyA list of critical parameters that need to be cross checked for accuracy

Sl. No Parameters

1 MS Temperature before Strainer Water leg correction maybe incorporated in onlineWater leg correction maybe incorporated in online2 MS Pressure before Strainer

3 HPT Exhaust Temperature

4 HPT Exhaust Pressure

be incorporated in onlinecritical pressuremeasurements used forperformance assessment

be incorporated in onlinecritical pressuremeasurements used forperformance assessment

5 HRH Temperature before Strainer

6 HRH Pressure before Strainer

7 IPT Exhaust Pressure

8 IPT Exhaust Temperature

9 Condenser Back Pressure

10 Condenser Water box dP10 Condenser Water box dP

11 Feed Water Flow

12 SH/RH Spray Flow

13 CW inlet/o tlet Temperat re13 CW inlet/outlet Temperature

14 Hotwell Temperature

15 All Extraction Pressures & Temperatures

CenPEEPCenPEEPDetermination of CT Performance

Importance of Tower Capability over Effectiveness

Acceptance Test Code for Water- Cooling Towers: CTI ATC - 105.

Effectiveness Capability►► Effectiveness is the ratio of range, to Effectiveness is the ratio of range, to the ideal range, i.e., difference between the ideal range, i.e., difference between

li t i l t t t dli t i l t t t d

►► Capability is as per CTI ATC Capability is as per CTI ATC –– 105 code.105 code.►► Capability is defined as the percentage of water that the tower Capability is defined as the percentage of water that the tower

cooling water inlet temperature and cooling water inlet temperature and ambient wet bulb temperature.ambient wet bulb temperature.

►► Effectiveness is the function of Range Effectiveness is the function of Range and Approach onlyand Approach only

can cool to the design cold water temperature when the can cool to the design cold water temperature when the parameters are all at their design value.parameters are all at their design value.►► Capability is function of inlet air WBT, Range, CW flow, fan Capability is function of inlet air WBT, Range, CW flow, fan power, wind velocity.power, wind velocity.

C bilit M d fl { D i KW f f }0 333and Approach onlyand Approach only

►► Effectiveness = Range / (Range + Effectiveness = Range / (Range + Approach). Approach). ►► Missing Factors:Missing Factors:

► Capability = Measured flow x { Design KW of fans}0.333

Predicted CW flow x {Test KW of Fans}0.333

►► Predicted CW flow is calculated from Manufacturer curves.Predicted CW flow is calculated from Manufacturer curves.►► CW Flow measurement : 3CW Flow measurement : 3--hole hole pitotpitot tube / Ultrasonic flow tube / Ultrasonic flow

tt►► Missing Factors:Missing Factors:•• Inlet air WBT• CW Flow• Wind velocity

F P

metermeter►► Multiple functional variables of independent nature.Multiple functional variables of independent nature.►► Comparability of CT Performance Comparability of CT Performance ►► Single Cell CT Capability as complementary measurement for Single Cell CT Capability as complementary measurement for P f E l tiP f E l ti• Fan Power

Effectiveness is used where ever Effectiveness is used where ever accurate CW Flow measurement is a accurate CW Flow measurement is a constraint.constraint.

Performance EvaluationPerformance Evaluation

42

CenPEEPCenPEEPImpact of Cooling Tower Performance 

Cold water temperature expected to improve by 2-3 deg C by improving Tower performance Cold water temperature expected to improve by 2-3 deg C by improving Tower performance

This will improve Condenser Vacuum by 6 – 9 mm Hg This will improve Condenser Vacuum by 6 – 9 mm Hg

Improvement in Heat Rate 12 – 18 kcal/kwhImprovement in Heat Rate 12 – 18 kcal/kwh

Reduction in fuel consumption of the order of 13524 - 20286 tons per year for one 500 MW unitReduction in fuel consumption of the order of 13524 - 20286 tons per year for one 500 MW unityear for one 500 MW unityear for one 500 MW unit

Reduction in CO2 emission of the order of 16905 - 25357 tons per year for one 500 MW unitReduction in CO2 emission of the order of 16905 - 25357 tons per year for one 500 MW unit

Annual savings of Rupees 18.8 – 28.2 million for one 500 MW unitAnnual savings of Rupees 18.8 – 28.2 million for one 500 MW unit

Assumptions : PLF ‐ 80%, GCV ‐ 3500 kcal/kg, Coal cost ‐ Rs. 1400 per ton

43

CenPEEPCenPEEP

25

CT Capability vs HR Loss (200 MW)Impact of Cooling Tower Performance 

15

20

25

/kw

hr) No standard curve was

l bl h / f

5

10

15

HR

Lo

ss

(Kc

al/

Seri…available with OEM / CTI for CTCapability vs Heat rate

0

5

96.7 92.5 88.7 85.1 81.8 78.8 76 72.5 70 67.9 65.8 63.8 62Capability (%) 25

CT Capability vs HR (500 MW)

15

20

Kca

l/kw

hr)

Typical curves were developed

5

10

LO

ss in

HR

(K

Series1for 200 MW & 500 MW units toassess the heat rate loss due topoor CT performance

440

5

97.4 95 91.6 88.4 85.4 82.7 80.1 77.6 75.3 73.2 71.1 69.2 67.3 65.6 64Capability (%)

CenPEEPCenPEEPOptimization of CT Performance

Concrete Splash Bars got damaged affecting the heat transfer. Complete splash bars replacement with concrete or PVC type improved the performance.

Choking of Film type fills due to airborne or waterborne dusts or silts. Mechanical cleaning or In-situ cleaning with water improved the performance. Replacement of 17 mm flute by 19 mm flute film packs also reduced choking.

45Nozzles getting choked due to balls coming from OLTC. Screens provided in hot water basin and the OLTC screens have been repaired.

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Falling of nozzles is repeated causing unequal water distribution

Optimization of CT Performance

Falling of nozzles is repeated causing unequal water distribution.

Plant and wild grass growth in Cooling Tower area obstructing the air flow.

Heavy algae growth on splash bars and tower structure affecting the performance.Heavy algae growth on splash bars and tower structure affecting the performance. Proper chemical treatment has improved the performance.

46

Reduced air flow through the tower affecting the performance. Air flow optimization done by adjusting the blade angle based on air flow or Fan power measurement.

CenPEEPCenPEEPOptimization of CT Performance

Inefficient air path that do not pass through the fill i.e. heat transfer zoneInefficient air path that do not pass through the fill i.e. heat transfer zone

Improper Sealing of shaft hole of fan.Improper Sealing of shaft hole of fan.

Improper Sealing of door openings of fan chamber.Improper Sealing of door openings of fan chamber.

Improper Sealing of the fan hub area.Improper Sealing of the fan hub area.

Increased blade tip clearancesIncreased blade tip clearances

Increased drift handled by fan due to damaged or missing drift eliminators. Replacement of drift eliminators has been done.Increased drift handled by fan due to damaged or missing drift eliminators. Replacement of drift eliminators has been done.drift eliminators has been done.drift eliminators has been done.Mud/slime deposit in the hot water basin resulting choking/ damage of nozzles. Cleaning of hot basins has been done. Mud/slime deposit in the hot water basin resulting choking/ damage of nozzles. Cleaning of hot basins has been done. Failure of gear boxes has decreased the availability of Cooling Tower fans i.e. failure of i t / t t h ft f il f b i f il f h l tFailure of gear boxes has decreased the availability of Cooling Tower fans i.e. failure of i t / t t h ft f il f b i f il f h l tinput / output shafts, failure of bearings, failure of worm wheels etc.input / output shafts, failure of bearings, failure of worm wheels etc.Mud or ash deposits in cold water basins. Two stage screening of CW water at CT outlet and proper cleaning of cold water basin have improved the performance.Mud or ash deposits in cold water basins. Two stage screening of CW water at CT outlet and proper cleaning of cold water basin have improved the performance.

Improper Chlorination & Shock dozing to maintain required FRCImproper Chlorination & Shock dozing to maintain required FRC

47

Improper Chlorination & Shock dozing to maintain required FRCImproper Chlorination & Shock dozing to maintain required FRC

Air recirculation from one tower to other Air recirculation from one tower to other

CenPEEPCenPEEPCooling Tower Thermal Performance Testing  

Grid setup for Cold Water Temp. measurement

Arrangement of three RTDs in Actual measurement of CWArrangement of three RTDs in a single pipe

Actual measurement of CW temperature at CT outlet channel

48

CenPEEPCenPEEPCooling Tower Thermal Performance Testing  

Grid setup for Cold Water Temp. measurement of single cell

Cold water temperature is being measured before it falls on basin

49

CenPEEPCenPEEPCW Flow Measurement

CW Flow measurement using 3 hole pitot tube on 

underground CW header

CW Flow measurement using

50

CW Flow measurement using ultrasonic flow meter

CenPEEPCenPEEPSingle Cell Air Flow measurement

The Anemometer is to be tied with rod (light in weight) with length equal to at least thein weight) with length equal to at least the radius of CT fan top portion. The length of cable connected to anemometer should also be more than the radius of CT fan top portionportion.

• Specific Power Consumption of CT Fan willindicate the Fill Condition

The Platform for proper approach for air flow measurement (at the top of

• Use of FRP blades in place of GRP bladesreduce Specific Power consumption

air flow measurement (at the top of the CT fan) with wheels at the bottom for mobility is to be made

51

CenPEEPCenPEEPCooling Tower Survey - Chandrapur

• The condition of splash bars to be assessed and repair/replacement isto be carried out as per condition.

• The capability test of cooling tower should be carried out

• The condition of splash bars to be assessed and repair/replacement isto be carried out as per condition.

• The capability test of cooling tower should be carried out• The airflow measurement at cooling tower fan outlet may be measured

along with fan power measurement. The high specific powerconsumption of CT fan indicates the choking of fills of cooling tower

• Design CW O/L Temp of CT is 34 deg C vis‐à‐vis design CW I/L to

• The airflow measurement at cooling tower fan outlet may be measuredalong with fan power measurement. The high specific powerconsumption of CT fan indicates the choking of fills of cooling tower

• Design CW O/L Temp of CT is 34 deg C vis‐à‐vis design CW I/L toDesign CW O/L Temp of CT is 34 deg C vis à vis design CW I/L tocondenser is 30 deg C

• Impact of 4 deg C increase in CW I/L Temp to Condenser is around 20kcal/kWh in GTCHRO ti f ibl d ti f li t b l d

Design CW O/L Temp of CT is 34 deg C vis à vis design CW I/L tocondenser is 30 deg C

• Impact of 4 deg C increase in CW I/L Temp to Condenser is around 20kcal/kWh in GTCHRO ti f ibl d ti f li t b l d• Options for possible up‐gradation of cooling tower may be exploredincluding upgradation of concrete splash bars to PVC splash bars inconsultation with CT vendors

• Options for possible up‐gradation of cooling tower may be exploredincluding upgradation of concrete splash bars to PVC splash bars inconsultation with CT vendors

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Th bili f li h ld b i d

Cooling Tower Survey - Panipat

• The capability test of cooling tower should be carried outincluding CW flow measurement to assess the performanceof cooling tower and to assess the heat rate loss due tocooling towercooling tower

• The CW flow measurement should be done using anultrasonic flow meter or by a pitot traverse preferably at CTultrasonic flow meter or by a pitot traverse preferably at CTinlet where sufficient straight length is available

• The condition of splash bars & nozzles to be assessed andprepair/replacement is to be carried out as per condition

• It is suggested to optimize the chlorine dozing in CW systemto avoid algae formation in cooling tower

• The cooling tower requires to be cleaned of deposits andl t th d it hi h i th h idit ff tiplant growth around it, which increases the humidity affecting

the performance of the cooling towers

CenPEEPCenPEEP

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