Heat Rate Computation Methodology Pe 329 100 n122,r 00

8/18/2019 Heat Rate Computation Methodology Pe 329 100 n122,r 00

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DOCUMENT TITLE: DOCUMENT NUMBER:

METHOD FOR COMPUTATION OF HEAT RATE PE-DC-329-100-N122 REV 00

PROJECT TITLE: NTPC-4x600MW OP JINDAL SUPER THERMAL POWER PROJECT PAGE 2 OF 11

1.0 HEAT AND MASS BALANCE ACROSS HP HEATERS:

Steam extractions to HP heaters is to be evaluated from thermal balance of the heaters. Feed water Mffw going to the economizer

comprises of the feed water quantities Ma and Mb coming from HP heater trains A and B respectively.

The heat and mass balance equations at this point are:

Ma+Mb = Mffw (A)

Ma.H5a + Mb.H5b = Mffw.H11 (B)

From these two equations, the value of Ma and Mb can be evaluated in terms of Mffw.

1.1 HEAT BALANCE ACROSS HPH-6A:

Ma.(H5a-H4a) = Za.(H10a-H6a) (C)

1.2 HEAT BALANCE ACROSS HPH-6B:

Mb.(H5b-H4b) = Zb.(H10b-H6b) (D)

1.3 HEAT BALANCE ACROSS HPH-5A:

Ma.(H4a-H3a) = Za.(H6a-H7a)+Ya.(H9a-H7a) (E)

1.4 HEAT BALANCE ACROSS HPH-5B:

Mb.(H4b-H3b) = Zb.(H6b-H7b)+Yb.(H9b-H7b) (F)

Putting the values of Ma and Mb in terms of Mffw, we can calculate the values of Za, Zb, Ya and Yb in terms of Mffw.


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2.0 HEAT AND MASS BALANCE ACROSS THE DEAERATOR:

M2.H2 = (Ya+Za).H7a+(Yb+Zb).H7b+X.H1+M1.H8 (G)

M2 = M1+X+Ya+Yb+Za+Zb± ΔMdea (H)

From the equations (G) and (H), the value of M2 can be calculated in terms of Mffw.

3.0 FINAL FEED WATER FLOW:

Mffw = M2 -Mrhs (I)

In the above equation, Mrhs is measured and M2 is calculated in terms of Mffw.

Hence, the value of Mffw can be calculated.

NOTE:

1.

When there is an increase in the level of Deaerator, -ve sign shall be used forΔ

Mdea.2.

When there is a decrease in the level of Deaerator, +ve sign shall be used for ΔMdea.3. When there is an increase in the level of Boiler Drum, -ve sign shall be used for ΔMdrum.

4. When there is a decrease in the level of Boiler Drum, +ve sign shall be used for ΔMdrum.

4.0 SUM OF STORAGES [ΔMsto] INCREASES OR DECREASES FOR THE FOLLOWING TANKS:

a)

Hotwell Storage b) Drum Storage

c) Condensate Make up storage

d) Deaerator Storage


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NOTE:

For the above storages if there is a net increase in the level, +ve sign is to be taken for ΔMsto and if there is a net decrease in level, -ve

sign is to be used for ΔMsto to arrive at the Total Cycle Losses to be reflected in the main steam flow [Mms].

Mms = Mffw± ΔMsto (J)

Reheat Steam Flow, Mrh = Mms-Za-Zb-Md+Mrhs (K)

5.0 SYMBOLS:

M1 = Mass flow measured from flow measuring device FP01 [Condensate flow to deaerator] ˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙ (Kg/hr)

Md = Gland leakages A, B and C from HP turbine to be computed ˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙ (Kg/hr)

ΔMsto = Total increase/decrease of storage in system [from level gauges] during test ˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙ (Kg/hr)

ΔMdea = Change in deaerator storage during the test ˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙ (Kg/hr)

ΔMdrum = Change in drum level during test ˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙ (Kg/hr)

X = Extraction steam flow to deaerator [Calculated from thermal balance] ˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙ (Kg/hr)

Ya = Extraction flow to HPH-5A [Calculated from thermal balance] ˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙ (Kg/hr)

Yb = Extraction flow to HPH-5B [Calculated from thermal balance] ˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙ (Kg/hr)

Za = Extraction flow to HPH-6A [Calculated from thermal balance] ˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙ (Kg/hr)

Zb = Extraction flow to HPH-6B [Calculated from thermal balance] ˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙ (Kg/hr)

H1 = Enthalpy of steam entering deaerator based on measurements PA21 & TW58, TW59 ˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙ (Kcal/kg)


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6.0 HEAT RATE:

Mms[Hms-Hffw] + Mrh[Hrho-Hrhi] + Mrhs[Hrhi-Hrhs]

HR = Pnet (L)

HR = Heat Rate (Kcal/KW.Hr)

Mms = Main steam flow at HPT inlet [As calculated] ˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙ (Kg/Hr)

Mrh = Reheat steam flow at IPT inlet [As calculated] ˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙ (Kg/Hr)

Mrhs = Reheater attemperation flow measured from Plant Flow measuring device FP06 & FP07 ˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙ (Kg/Hr)

Hms = Enthalpy of steam before ESV based on measurements PD01 to PD02 & TW03 to TW06 ˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙ (Kcal/Kg)

Hffw = Enthalpy of final feed water after HP heaters based on measurements PD25, PD26 & TW51, TW52˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙

(Kcal/Kg)

Hrho = Enthalpy of Hot Reheat steam before IV based on measurements PD11 to PD12 & TW21 to TW24 ˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙ ̇(Kcal/Kg)

Hrhi = Enthalpy of Cold Reheat steam based on measurements PD04 & TW07 to TW08 ˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙ (Kcal/Kg)

Hrhs = Enthalpy of Reheater attemperation based on measurements PD27, TW64 & TW65 ˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙ (Kcal/Kg)

Pnet = Pgen-Paux ˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙ (kW)

Pnet = 600MW for 100% MCR

Pgen = Power measured at Generator Terminals ˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙ (kW)

Paux = Power required for Integral Auxiliaries ˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙˙ (kW)

NOTE:


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1. POWER REQUIRED FOR INTEGRAL AUXILIARIES-

For all the auxiliaries included in the Heat Rate calculations, the design values shall be considered in arriving at the total AuxiliaryPower [Paux] to be deducted from the power measured at the generator terminals [Pgen] in the Heat Rate formula.

DEATIL FOR INTEGRAL AUXILIARIES:

1. Oil Vapor Exhauster 0.75 kW

2.

CF Pump & CF Vapour Exhauster 110.00 kW3. Circulating Pump for CF purification system 0.75 kW

4. Generator Auxiliary power requirements 35.00 kW

5. GSC Exhauster 3.00 kW

TOTAL 149.50 kW (≈ 150 kW)

7.0 COMPUTATION OF TOTAL GLAND LEAKAGES:

Steam leakage through the glands A, B and C is calculated using the formula given below:

[P12 – P2

2]

G = K ―――――

[P1.V1]

G = Steam Leakage through the Glands (T/Hr)

P1 = Pressure before the Glands (Ata)

P2 = Pressure after the Glands (Ata)

V1 = Specific volume at inlet conditions to the Glands (m3/kg)


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Data for design case is given below [Refer HBD No. PE-DC-329-100-N151, REV 00]

PARAMETER HPT INLET END HPT OUTLET END

G 2.648 3.487

P1 45.00 45.00

P2 7.13 7.13V1 *0.07565 **0.057896

* Based on 45 Ata and 810.7 Kcal/kg.** Based on 45 Ata and 337.0°C.

For design case P1, P2 and V1 and G are known and hence K can be evaluated.

K values calculated for the design case are as given below:

A) For Gland Leakage from HPT inlet end K = 0.10996

B)

For Gland Leakage from HPT outlet end K = 0.12668

For test case, by putting this value of K and the test values of P1, P2 and V1 the computation of G can be done.

For the test case, the values of P1, P2 and V1 are determined as given below:

FOR HPT INLET END:

P1 is based on measurements PD04P2 is based on measurements PA05 to PA06

V1 is based on measurements PD04 and Ta

Ta is calculated on the basis of PD04 and Enthalpy correspondinmg to PD01, PD02 and TW03 to TW06.


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FOR HPT OUTLET END:

P1 is based on measurements PD04P2 is based on measurements PA05 and PA06

V1 is based on measurements PD04 and TW11, TW12

8.0 NOTE:

1.0 The Heat Rate is guaranteed with 0% makeup and hence no makeup will be supplied to the condenser during the PG test. Under

these conditions the storage in the deaerator feed storage tank and Hotwell are utilized towards the leakages losses and the measured

Heat Rate shall be corrected using the correction curves viz. change in Heat Rate vs. change in storage of feed water storage tankand change in Heat Rate vs change in Hotwell Level.

2. 0 In case the temperature measured at the HP turbine exhaust [measurements TW07 to TW08] is less than the temperature ofextraction steam at HP Heater No. 6 inlet or the Temp. at downstream of mixing of HP Bypass [measurements TW15 to TW18 or

TW09 & TW10] then leakage through the HP bypass valve is suspected. The leakage shall be estimated as given below: -

[ Mms - Md ] [ H10 - Hrhi ]

Mhpb =

[ Hms - Hrhi ]

Where, Mhpb = Quantity of steam leakage through the HP bypass valve

Value of H10 will be based on measurement TW09, TW10 & PD05The quantity of steam entering the HP turbine [Mmsl] shall be corrected for the leakage through the HP bypass as given below and shall be used in the equation (L) instead of Mms.

Mmsl = Mms - Mhpb


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9.0 GUARANTEE CONDITION:

1. Guaranteed Heat Rate at:

A) 100% LOAD = 1944.0 Kcal/KWHr

(Refer HBD Nos. PE-DC-329-100-N151 REV00, Titled “600MW, 0%MU, 76 mm Hg ATA BACK PR.”)

2. The total tolerance on Heat Rate due to instrument uncertainty shall be ±1.0%.

3. The PG test shall be conducted with valves wide-open position by suitably adjusting the main steam pressure.

4. If the test is carried out later than three (3) months, after the date of commissioning, due to any reason whatsoever, the specific heat

consumption shall be increased by 0.1% for each month or part of a month by which the period between the initial commissioning and

the acceptance test exceeds 3 months.

5. The pressure drop between MS strainer and ESV & between ESV and HPT in the MS line and between HRH strainer and IV & between IV & IPT in HRH line have not been considered in the heat balance calculations since same is to be accounted in the

respective system piping pressure drops. The actual pressure drops shall be estimated during the PG test based on layout envisagedand the calculated steam flows and necessary corrections applied on the measured pressures.

10.0 LIST OF CORRECTION CURVES:HEAT RATE CORRECTION CURVES:

1. Main Steam Pressure

2.

Main Steam Temperature3. Reheat Steam Temperature

4. Back Pressure

5. Change in Feed Water Storage in Deaerator FW storage tank6. Change in Hot Well Level

7. Power Factor

8. Frequency

9. Generator Hydrogen Pressure


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10. Generator Voltage

11.

SH Spray12. RH Spray

13. RH circuit pr. drop14. Change in Feedwater economiser inlet Pressure

OUTPUT CORRECTION CURVES:

1. Main Steam Pressure2. Main Steam Temperature

3. Reheat Steam Temperature

4.

Back Pressure5. Change in Feed Water Storage in Deaerator FW storage tank

6. Power Factor

7. Frequency

8. Generator Hydrogen Pressure9. Generator Voltage

10. Auxiliary Steam Consumption

11. Make Up to Hot Well

12.

SH Spray13. RH Spray

14. RH circuit pr. drop15. Change in Feedwater economiser inlet Pressure

Heat Rate Computation Methodology Pe 329 100 n122,r 00

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