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BOILERHEAT INPUT LOSSES

USEFUL OUTPUT

HEAT IN STEAM

EFFICIENCY = L = HEAT INPUT)(HEATOUTPUT/ * 100

HEAT OUTPUT = HEAT INPUT - LOSSES

EFFICIENCY = L =[(HEAT INPUT - LOSSES)/ HEATINPUT]*100

= (1- LOSSES/ HEAT INPUT )*100

= 100-%LOSSES

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Boiler Efficiency

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HEAT INPUTHi=Qc*Hc*1000

WHEREHi - HEAT INPUT Kcal/Hr

Hc - CALORIFICVALUE OF FUEL Kcal/Kg

QC - COAL FLOW T/Hr

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HEAT OUTPUTHo =[{(Qs*Hs)-(Qf*Hf)}+{Qr*(Hro-Hri)}]*100

Kcal/HrWHERE

Qs

- MAIN STEAM FLOW T/HrHs - MAIN STEAM ENTHALPY Kcal/KgQf - FEED WATER FLOW T/Hr

Hf - FEED WATER ENTHALPY Kcal/KgQr - R.H STEAM FLOW T/Hr

Hro - H.R.H STEAM ENTHALPY Kcal/Kg

Hri - C.R.H STEAM ENTHALPY Kcal/Kg

Ho - HEAT OUTPUT Kcal/Hr

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BOILER EFFICIENCYCALCULATION DIRECT

METHOD

Qs - MAIN STEAM FLOW 600MAIN STEAM PRESSURE K2 140

MAIN STEAM TEMPERATURE 0C 540

Hs - MAIN STEAM ENTHALPY Kcal/Kg819.97

Qr - R.H STEAM FLOW 563C.R.H. STEAM PRESSURE K2 40

C.R.H. STEAM TEMPERATURE 0C 330

Hri - C.R.H. STEAM ENTHALPY Kcal/Kg727.18

H.R.H. STEAM PRESSURE K2 38H.R.H. STEAM TEMPERATURE 0C 540

Hro - H.R.H. STEAM ENTHALPY Kcal/Kg845.15

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BOILER EFFICIENCYCALCULATION

DIRECT METHOD

Qf- FEED WATER FLOW T/Hr

F.W. PRESSURE 2 160

F.W TEMPERATURE 0C 540

Hf- FEED WATER ENTHALPY Kcal/Kg 237.3Ho - HEAT OUTPUT 41,36,63,800

[{(Qs*Hs)-(Qf*Hf)}+{Qr*(Hro-Hri)}]*1000

QC - COAL FLOW 110

Hc - CALORIFICVALUE OF FUEL Kcal/Kg 4300Hi - HEAT INPUT 47,30,00,000

Qc*Hc*1000

EFFICIENCY = Ho/Hi =87.46 %

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BOILER EFFICIENCYCALCULATIONDIRECT METHOD

ACCURATE MEASUREMENT OFFUEL QUANTITY,HEATING VALUE,FEEDWATER AND STEAM

QUANTITIES AND OTHERPARAMETERS ARE REQUIRED

ANY ERROR IN MEASUREMENT OF

THE ABOVE WILL MAGNIFY THEEND RESULT BY FOUR OR FIVETIMES

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Direct method / Input Output method

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BOILER EFFICIENCY CALCULATIONINDIRECT/LOSSES METHOD

MORE INFORMATIVE

INDIVIDUAL LOSSES AREESTABLISHED FOR COMPARISON

MEASUREMENTS WILL BE SIMPLE AS TOTAL LOSSES ARE ONLY 10 TO

20% OF HEAT INPUT ANY ERROR

IN SAMPLING AND ANALYSISAFFECT THEEND RESULT ONLYMARGINALLY

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LOSSES CALCULATED COMBUSTIBLE IN ASH/CARBON LOSS

DRY GAS LOSS LOSS DUE TO MOISTURE IN FUEL

LOSS DUE TO HYDROGEN IN FUEL

LOSS DUE TO MOISTURE IN AIR LOSS DUE TO SENSIBLE HEAT OF

BOTTOM ASH

LOSS DUE TO SENSIBLE HEAT OF FLY

ASH

MILL REJECTS LOSS

RADIATION LOSS

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REQUIREMENTS FORCALCULATING LOSSES

FUEL ANALYSIS

PROXIMATE

ULTIMATE

CALORIFIC VALUE

FLUE GAS ANALYSIS

ASH ANALYSIS FOR CARBON BOTTOM ASH

FLY ASH

AMBIENT AIR TEMPERATURE A.H.GAS OUTLET TEMPERATURE

RATE OF MILL REJECTS

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COMBUSTIBLE IN ASH/CARBON LOSSASH IN COAL A%

FLY ASH DISTRIBUTION DF%

BOTTOM ASH DISTRIBUTION DB%

FLY ASH COMBUSTIBLES CF%

FLY ASH COMBUSTIBLES UF=A*DF*CF/{100*100*(100-CF)}

Kg/Kgf

BOTTOM ASHCOMBUSTIBLES CB%

BOTTOM ASH COMBUSTIBLES UB=A*DB*CB/{100*100*(100-CB)}

Kg/Kgf

TOTAL COMBUSTIBLES U =( UF+UB ) Kg/Kgf

CALORIFIC VALUE OF COMBUTIBLES = 8077.8 Kcal/Kg

GROSS CALORIFIC VALUE OF COAL = GCV Kcal/Kg

CARBON LOSS = U*8077.8*100/GCV %

40

85

1.3

0.0045

15

10.2

0.0068

0.0113

4267.00

2.14

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DRY GAS LOSS

CARBON IN COAL C%

SULPHUR IN COAL S%TOTAL COMBUSTIBLES Ukg/Kgf

Sp. HEAT OF GAS Cp KJ/Kg mol 0C

F.G.TEMP. AT A.H. OUTLET Tg0C

AMBIENT TEMP. Ta0C

CO2 IN F.G.AT A.H. OUTLET CO2%

GROSS CALORIFIC VALUE OF COAL GCV Kcal/Kg

WEIGHT OF DRY GAS Wd {(C+S/2.67)-100U}/12CO2 Kgmol/Kgf

SENSIBLE HEAT OF DRY GAS SH KJ/Kg

=Wd*Cp*(Tg-Ta) KJ/Kg

DRY GAS LOSS {SH/ (4.186*GCV)}*100 %

42.52

0.420.011332.00

156.00

28.00

14.20

4267.00

0.244

999.42

5.60

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LOSS DUE TO MOISTURE IN FUEL

MOISTURE IN FUEL M%

F.G.TEMP. AT A.H. OUTLET Tg0

CAMBIENT TEMP. Ta 0CGROSS CALORIFIC VALUE OF COAL GCV Kcal/Kg

SENSIBLE HEAT OF WATER VAPOUR SW KJ/Kg

SW=1.88*(Tg-25)+2442+4.2*(25-Ta) KJ/Kg

LOSS DUE TO MOISTURE=SW*M/(4.186*GCV) %

10.4

156.0028.004267.00

2675.68

1.56

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LOSS DUE TO HYDROGEN IN FUEL

HYDROGEN IN FUEL H %LOSS DUE TO H2 IN FUEL 9*H*SW/(4.186*GCV) %

3.24.31

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LOSS DUE TO MOISTURE IN AIRCARBON IN FUEL C %

HYDROGEN IN FUEL H %

SULPHUR IN FUEL S %OXYGEN IN FUEL O %

GROSS CALORIFIC VALUE OF COAL GCV Kcal/KgAMBIENT TEMPERATURE (DRY ) Ta 0 CAMBIENT TEMPERATURE (WET) TW

0 C

EIGHT OF MOISTURE (FROM CHART) MWV Kg/Kg AIRSTOCHIOMETRIC AIR SA

SA= (2.66C+8H+S-O)/23.2 Kg/Kgf

O2 AT A.H. OUTLET O2 %

TOTAL AIR INCL.EXCESS AIR EA = 21/(21-O2) Kg/Kg SA

TOTAL MOISTURE IN AIR=MA=SA*EA* MWV Kg/KgfF.G.TEMP. AT A.H. OUTLET Tg 0C

LOSS DUE TO MOISTURE IN AIR

=MA*1.88*(Tg-Ta)*100/(4.186*GCV) %

42.523.2

0.426.5

426728

0.02

5.72

5.8

1.38

0.22156

0.3

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LOSS DUE TO SENSIBLE HEAT OFBOTTOM ASH

TEMP.OF BOTTOM ASH ABOVE AMBIENT TB0C

SP. HEAT OF BOTTOM ASH CPB Kcal/Kg0C

ASH IN COAL A %

BOTTOM ASH DISTRIBUTION DB%GROSS CALORIFIC VALUE OF COAL GCV Kcal/Kg

LOSS DUE TO SENSIBLE HEAT OF BOTTOM ASH

=A*DB*CPB*TB*100/(100*100*GCV) %

700

0.25

40.0

154267

0.25

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LOSS DUE TO SENSIBLE HEAT OFBOTTOM ASH

TEMPERATURE OF FLY ASH Tg0

CSPECIFIC HEAT OF FLY ASH CPF Kcal/Kg 0C

DISTRIBUTION OF FLY ASH DF %

LOSS DUE TO SENSIBLE HEAT OF FLY ASH

A*DF*CPF*(Tg-Ta)*100/(100*100*GCV) %

1560.2

85

0.2

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LOSS DUE TO MILL REJECTS

RATE OF MILL REJECTS WRE Kg/Hr

FLOAT OF MILL REJECTS F %

CALORIFIC VALUE OF MILL REJECTS CVR Kcal/Kg

CVR = F*GCV/100

DESIGN FUEL FLOW WFD Kg/Hr

GROSS C.V. OF DESIGN FUEL GCVD Kcal/Kg

ACTUAL FUEL FLOW WFA Kg/Hr

WFA = WFD* GCVD / GCV

WEIGHT OF MILL REJECTS WR Kg/Kgf

WR = WRE/WFA Kg/Kgf

HEAT LOSS DUE TO MILL REJECTS

= WR*CVR*100/GCV %

50

5

213.3

9000

450

94910

0.0005

0.0025

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ABSTRACT OF BOILER LOSSES

CARBON LOSS 2.14 %

DRY GAS LOSS 5.60 %

LOSS DUE TO MOISTURE 1.56 %

LOSS DUE TO H2 IN FUEL 4.31 %

LOSS DUE TO MOISTURE IN AIR 0.30 %

LOSS DUE TO S.H OF BOTTOM ASH 0.25 %

LOSS DUE TO S.H OF FLY ASH 0.20 %

LOSS DUE TO MILL REJECTS 0.0025%

RADIATION LOSSES 0.21 %

TOTAL LOSSES

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BOILER EFFICIENCYEFFICIENCY = 100-TOTAL LOSSES

= 100-14.57

= 85.43 %

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Determination of CompleteAnalysis of Coal from

Proximate AnalysisFixed Carbon - FC%

Volatile Matter - V%

Moisture - M%

Ash - A%

Hydrogen - H = V*[7.35/(V+10)-0.013]

Nitrogen - N = 0.07V for Anthracite

2.10-0.012V forBituminous

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Proximate AnalysisTotal Carbon C= Fixed carbon+Vol.carbon

= FC+0.02 V2 for

Anthracite

= FC+0.9(V-14) forbituminous

= FC+0.9(V-18) forlignite

Oxygen = 100-(H+C+N

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Proximate AnalysisProximate analysis

Ash 36

Moisture 15.0

Volatile Matter 22.8%

Fixed Carbon 25.38%

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A Ash % 36.82

M Moisture % 15.00

VM Volatile Matter % 22.80FC Fixed Carbon % 25.38

FC FC Without

Moisture and Ash

(FC*100)/

100-(M+A)

% 52.68

VM VM Without

Moisture and Ash

100-FC

% 47.32

C Carbon Without

Moisture and Ash

FC+0.9(VM-18)

% 79.07

C [C*{100-(M+A)]

/100

% 38.09

H Hydrogen

Without Moisture

and AshVM*

[{7.35/(VM+10)

}-0.013]

% 5.45

H [H*{100-(M+A)]

/100

% 2.62

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QUICK ESTIMATION OF BOILER

PERFORMANCE PARAMETERS

1.T EORITICAL R AIR REQUIREMENT

Th. ry Air [TA ] Kg./Mkcal. Coal 1360

Oil - 1325

as 1300

2.QUALIT &COMPOSITION OF FUEL

igher eating alue Kcal/Kg

[83.052*FC 57.992* M-14.178*AS -43.611*MOISTURE 797.746]

3.EXCESS AIRO2

EAi ( ) _____________ 1

21 - O2

K1 1.0 for coal, 0.9 for oil, 0.92 for gas

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QUICK ESTIMATION OF BOILER

PERFORMANCE PARAMETERS

4.O2 0N DRY BASIS

O2 o Dry basis % = O2 o Wet basis / K2

K2 =0.9 for coal, 0.87 for oil, 0.81 for gas

5.AIR & AS QUANTITY

Air Qua tity WAI [ Kg./s ] = WTA* *{1 (EAi / 100)}*1.02*WF*10-6

WF =Fuel Qua tity Kg/s

Wet gas Qua tity at a y sectio ca be calculated from excess air levelcalculated from t e fluegas O2 % i t at sectio .

as Qua tity WI [ Kg./s ] = WF *[WTA* *{1 (EAi/100)}*1.02* 10-6

(As /100) 1]

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VOLUMETRIC FLYASH SAMPLE

COLLECTION AND ANALYSIS

According to the ASME Test Code PTC 38Determining the Concentration of ParticulateMatter in a Gas Stream; ideally test tap layoutshould be such that sampling access ports and

traverse points are selected to permit samplingin zones of equal areas. The traverse gridshould facilitate a minimum of one traversepoint for every 9 ft of duct area. For examplea 12 18 duct with a cross-sectional area of

216 ft will require a minimum of (24) traversepoints.

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VOLUMETRIC FLYASH SAMPLE

COLLECTION AND ANALYSIS

The traverse grid should be located in a straightrun of ductwork (constant cross-sectional area),

preferably a vertical run in order to minimize

stratification of the medium. In addition, the

traverse grid should be located a minimum ofeight (8) duct diameters downstream and two (2)

duct diameters upstream from the nearest flow

disturbance. Since these criteria are often

impossible to meet, test taps are generally

located in the best possible location. This isacceptable if all parties involved in the testing

agree. Adequacy of probe access, lighting, power

facilities, etc. should also be considered when

choosing a location

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Vol metric Fly as Sample Collectio

a d A alysis

Example of Eq al Area Sampli g Grid

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Typical locatio s for collectio of a fly as sample

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Proced re for Sievi g a Flyas

Sample

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Procedure for Burning a Flyash

Sample for L.O.I. Determination

Label each of the crucibles.

Preheat the crucibles to 150 C for

approximately 15 minutes. Weigh each crucible while

hot(Wc).

Add one gram of the ash to beburned to the crucible as it remainson the scale and record thesample and crucible weight.

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Insert the crucible with the sampleinto the oven and leave it for 1hour at between 150 - 260 C.

Remove the crucible with sampleand reweigh and record it,comparing the weight to the initial

weight. Any difference in the two is the

amount of water driven off.

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Replace the crucible w/sample inthe oven at 150 - 260 C and leave

it for 30 minutes.

Remove, weigh, and record thecrucible w/sample.

Continue this process until theweight remains constant.

RECORD THIS WEIGHT(WCSD).

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Replace the crucible w/sample inthe oven and cook the sample at

815 C for three (3) hours. Remove, weigh, and record the

crucible w/sample weight.

Replace the crucible w/sample andcook at 815 C for 30 minutes.

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Remove, weigh, and record thecrucible w/sample weight.

Any difference indicates that thereis still carbon present in the ash.

Continue this procedure until the

weight remains constant(WCSFW).

P d f B i Fl h

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Once the weight no longer changes, theflyash L.O.I. can be calculated using thefollowing equation:

WCSD = Crucible w/sample (dried)weight

WCSFW = Crucible w/sample (finalweight)

WC = Crucible weight

% Flyash L.O.I.

= {[(WCSD - WC) - (WCSFW - WC) 100]}

(WCSD - WC)

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