1. BOILER EFFICIENCY Heat Input is Pulverised Coal
Steam Output
Radiation Loss
Second Pass
Heat Input
ESP
Furnace
Heat Input is Pulverised Coal
Heat Output is Superheated Steam

2. Efficiency Calculations
Standard Applied :- ASME Standard PTC 4.1
Calculation Method :- Loss Method
Losses calculated as percentage of INPUT as 100%

3. Losses in Boilers 1) Loss due to dry flue gas = 4.928% Heat Input
Second Pass
Heat Input
Furnace
ESP
1) Loss due to dry flue gas = 4.928%    

4. Losses in Boilers Contd.
Second Pass
Heat Input
ESP
Furnace
2) Loss due to Unburnt Carbon   = 0.331%

5. Losses in Boilers Contd.
Second Pass
Heat Input
ESP
Furnace
3) Due to Sen. Heat of Bottom Ash      =  0.071%
4) Due to Sen. Heat of Fly Ash      =  0.102%

6. Losses in Boilers Contd.
Second Pass
Heat Input
ESP
Furnace
5) Radiation Losses                  = 0.200%

7. Losses Related to Coal & Ambient Air Quality
6) Loss due to moisture in Fuel =  1.263%
7) Loss due to Hydrogen in Fuel =  5.537%
8) Loss due to Moisture in Air    =  0.074%
9) Unaccounted Losses   = 1.327%
    Total Losses                     = 13.83%

8. Data required for Boiler Efficiency Calculations
Unit load MW FW Flow at Econ inlet T/hr Wet bulb Temp 0C Dry bulb Temp 0C Barometric Pressure mmHg Total Coal Flow T/hr Unburnt C in BA % Unburnt C in FA % Radiation & Unaccounted Losses % % Fly ash to Total Ash % % Bottom ash to Total ash %

9. Data required……….2 Proximate Analysis of Coal Air Dry As fired
Moisture % % Ash % % Volatile Matter % % Fixed Carbon % % Gross Cal. Value Kcal/kg Kcal/kg
Ave FG O2 APH in Ave FG O2 APH Out Ave FG CO2 APH in Ave FG CO2 APH Out Ave FG CO APH in Ave FG CO APH Out Ave. FG Temp APH in Ave. FG Temp APH Out Air to APH in Air APH out Total Primary Flow Total Air Flow L Total Air Flow R Design Ambient / Ref air Temp

10. Calculations Ultimate Analysis As fired Basis
1. Carbon = (Fixed Carbon AD+0.9(Vol Matter AD-14)) *GCV AF/GCV AD
2. Sulphur = 0.4 * GCV AF/GCV AD
3. Hydrogen = Vol.Matter AD*(7.35/(Vol Matter AD+10) )* GCV AF/GCV AD
4. Moisture = Moisture AF
5. Nitrogen = ( * Vol.Matter AD)* GCV AF/GCV AD
6. Oxygen = 100-(Carbon+Hydrogen+Nitrogen+Ash AD+Moisture AD)* GCV AF/GCV AD
7. Ash = Ash AF and 8. Gross Cal. Value=GCV AF

11. Calculations ….. Losses
Dry Gas Loss = Sensible heat of dry gas*100/(GCV AF*4.186) %
Carbon in fuel %
Sulfur in fuel
Carbon in ash / kg of fuel
kg/kg coal
Specific Heat of Gas
kg/kg C
Avg. Flue gas temp - APH Out 0C
Unburned C in Ash = Pfa/100*Cfa + Pba/100*Cba
C in Ash / Kg of coal =A/100*Cash/(100-Cash) kg
Total air Flow = A+B
Thr
Ratio SA Flow to Total Air Flow - Fsa/Fta
Ratio PA Flow to Total Air Flow = Fpa/Fta
Weighted Temp Air In = Tsai*Rsa+Tpai*Rpa
0CWeighted Temp Air Out = Tsao*Rsa+Tpao*Rpa
0C 
Avg. Flue Gas CO2 -APH Out
Gross CV
kcal/kg
Weight of Dry Gas = (Ca+S/ *U)/(12*CO2out)
Sensible Heat Dry Gas = Wd*30.6(Tgo-Trai)
kJ/kg

12. CONTROLLABLE LOSSES 1 FOLLOWING LOSSES CAN BE CONTROLLED
1. LOSS DUE TO DRY FLUE GAS
THE DESIGNER GIVES THIS LOSS AT THE FLUE GAS
APH OUTLET TEMP OF 1400C
ANY INCREASE IN THE FGT MORE THAN 1400C WILL BE RESULTING IN MORE LOSSES. THIS TEMP HAS TO BE CONTROLLED BY PROPER CLEANING OF THE FURNACE

13. CONTROLLABLE LOSSES 2a
LOSSES DUE TO THE UNBURNT COAL IN BOTTOM AND FLY ASH.
LOSS DUE TO UNBURNT IN BOTTOM ASH
THE DESIGNER GIVES THIS %AGE AS MAX 4.8 % ANY INCREASE IN THIS PERCENTAGE BEYOND THIS WILL RESULT IN MORE LOSSES
IF UNBURNT IN BOTTOM ASH IS MORE, THE CULPRIT IS THE COAL MILL, CHECK THE FINENESS OF PULVERISED COAL. CHECK THE % RETENTION ON 50 MESH. IT SHALL NOT EXCEED 1%.

14. CONTROLLABLE LOSSES 2b
CHECK THE UNBURNT IN FLY ASH SAMPLE TAKEN FROM THE FIRST HOPPER OF ESP/BF
AS PER THE DESIGNER IT SHALL NOT EXCEED 0.8%.
IF UNBURNT IN FLY ASH EXCEEDS 0.8% IT INDICATES INCOMPLETE COMBUSTION DUE TO LESS AMOUNT OF AIR
CHECK FOR O2 % AT THE APH FG INLET FOR 2.8%, INCREASE IF NECESSORY TO 3.2%. AGAIN CHECK FOR UNBURNTS IN FLY ASH. SIMULTANIOUSLY CHECK FOR AIR LEAKAGES/INGRESS IN THE SECOND PASS

15. Losses Calculations Assumptions:- Fly Ash is 80% of Total Ash.
Bottom Ash is 20% of Total Ash
Sulphur is 0.4% in Coal

16. Proximate Analysis of Coal
DATA REQUIRED
Fuel Properties
Proximate Analysis of Coal
Air Dry Basis As Fired basis
Moisture % Moisture %
Ash % Ash %
Volatile Matter % Volatile Matter %
Fixed Carbon % Fixed Carbon %
Gross Cal. Value % Gross Cal. Value %

17. Data Required contd. Unit load MW FW Flow at Econ inlet T/hr
Wet bulb Temp 0C
Dry BulbTemp 0C
Barometric Pressure
Total Coal Flow T/hr
Unburnt Carbon in BA %
Unburnt Carbon in FA %

18. Data Required Contd. ** Ave FG O2 APH in ** Ave FG CO2 APH in
** Ave FG CO APH in ** Ave FG O2 APH Out
** Ave FG CO2 APH Out ** Ave FG CO APH Out
** Air to APH in Temp ** Air APH out Temp
** Total Air Flow L ** Total Air Flow R
** Ave. FG Temp APH in
** Ave. FG Temp APH Out
** Total Primary Air Flow

19. GCV Calculations for Coal
Calculations of GCV 
As fired Basis
Coal sample is taken as received basis, heated for calculation of
A) Total Moisture content = TM%
 Air Dry Basis
The sample is air dried for removal of surface moisture and burned completely for
A) Inherent moisture content = M %
B) Ash percentage = A %

20. GCV Calculations for Coal Contd.
1) Useful Heat Value = 8900 – 138(A%+M%) kcal/kg
2) Gross Calorific Value = (UHV – 75.4 M%)/1.466
(Air Dry Basis) Kcal/kg
3) Ash % (As fired basis) = [A %] (100 - TM%)/(100 – M%) %
4) Gross Calorific Value = [GCVAD] (100 - TM%)/(100 – M%)
(As fired Basis) Kcal/kg
5) Net Calorific Value = [GCV] – 10.02M% Kcal/kg

21. Calculations Weight of Dry Gas = (Ca+S/2.67-100*U)/(12*CO2out)
Ca = % Carbon in fuel (Ultimate Analysis as Fired)
S = % Sulfur in fuel (Ultimate Analysis as Fired)
A = % of Ash in fuel (Ultimate Analysis as Fired)
Unburned C in Ash = Pfa/100*Cfa + Pba/100*Cba
U = Carbon in ash / kg of fuel=A/100*Cash/(100-Cash)
CO2 Out = Avg. CO2 Flue Gas -APH Out
Sensible Heat Dry Gas = Wd*30.6(Tgo-Trai)