





















Table 13A








Combustion Calculations  Btu Method


























INPUT
CONDITIONS  BY TEST OR SPECIFICATION


FUEL DATA  Coal









1

Excess air at economizer exit, % by weight



15

Ultimate Analysis

16

Theo. Air, lb/100lb fuel

17

H20, lb/100 lb fuel



2

Entering air temperature, ^{O}F



Constituent

% by wt.

K1

[15] x K1

K2

[15] x K2



3

Reference air temperature, ^{O}F


A

C










4

Fuel temperature, ^{O}F


B

S










5

Flue gas temp leaving AH (including leakage), ^{O}F


C

H_{2}









6

Flue gas temp leaving AH (excluding leakage), ^{O}F


D

H_{2}O





1.00




7

Moisture in air, lb/lb dry air


E

N_{2}










8

Additional moisture lb/100 lb fuel


F

O_{2}


4.32







9







G

Ash











10







H

Total










11







18

Higher heating value (HHV), Btu/lb fuel




12







19

Unburned carbon loss, % fuel input




13







20

Theoretical air, lb/10,000 Btu

[16H] x 100 / [18]




14







21

Unburned carbon, % of fuel

[19] x [18] / 14,500




COMBUSTION
GAS CALCULATIONS, Quantity / 10,000 Btu Fuel Input



22

Theoretical air (corrected), lb/10,000 Btu

[20]  [21] x 1151 / [18]




23

Total Residue from fuel, lb/10,000 Btu

([15G] + [21]) x 100 / [18]




24



























A

At Burners

B

Leakage

C

Leaving Furnace

D

Leaving Air Heater



25

Excess air, % by weight


















26

Dry air, lb/10,000 Btu

(1 + [25] / 100) x [22]









27

H20 from air, lb/10,000 Btu

[26] x [7]







28

Additional Moisture, lb/10,000 Btu

[8] x 100 / [18]







29

H20 from fuel, lb/10,000 Btu

[17H] x 100 / [18]







30

Wet gas from fuel, lb/10,000 Btu

(100  [15G]  [21]) x 100 / [18]









31




















32




















33

Total wet gas, lb/10,000 Btu

Summation [26] through [30]









34

Water in wet gas, lb/10,000 Btu

Summation [27] + [28] + [29]







35

Dry gas, lb/10,000 Btu

[33]  [34]







36

H20 in gas, % by weight

[100] x [34] / [33]







37

Residue, % by weight

100 x [24] / [33]







EFFICIENCY
CALCULATIONS, % Input from Fuel




Losses



38

Dry Gas, %

0.0024 x [35D] x ([6]  [3])










39

Water from

Enthalpy of steam at 1 psi, T = [6]

H_{1} =
(3.958E5 x T + .4329) x T + 1062.2





40

Fuel,

Enthalpy of water at T = [3]

H_{2} = [3] 
32





41

asfired %





[29] x ([39]  [40]) / 100









42

Moisture in air, %

0.0045 x [27D] x ([6]  [3])









43

Unburned carbon, %

[19] or [21] x 14,500 / [18]









44

Radiation and convection, %

ABMA curve









45

Unaccounted for and manufacturers margin, %















46




















47

Summation of losses, %

Summation [38] + [46]











Credits



48

Heat in dry air, %

.0024 x [26D] x ([2]  [3])









49

Heat in moisture in air, %

.0045 x [27D] x ([2]  [3])









50

Sensible heat in fuel, %

(H at T[4]  H at T[3]) x 100 / [18]






0.00



51

Other, %












0.00



52

Summation of credits, %

Summation [48] through [51]









53

Efficiency, %

100  [47] + [52]























