Page 36 - Handbook of Energy Engineering Calculations

In this calculation, the temperature correction factor 2.15 = absolute flue-
gas temperature,°R/absolute atmospheric temperature,°R = (600 + 460)/(32 +
460). The total weight of N in the flue gas is the sum of the N in the
2
2
combustion air and the fuel, or 10.4580 + 0.0022 = 10.4602 lb (4.707 kg).

5. Compute the CO content of the flue gas
2
CO , wet basis = 55.0/387.82 = 0.142, or 14.2 percent. CO , dry basis =
2
2
55.0/(387.2 − 43.5) = 0.160, or 16.0 percent.

6. Compute the air required with stated excess flow
The pounds (kilograms) of air per pound (kilogram) of oil with 20 percent

excess air = (1.20) (13.6176) = 16.3411 lb (7.353 kg) of air per pound
(kilogram) of oil burned.

7. Compute the weight of the products of combustion
The weight of the products of combustion = product weight for perfect

combustion, lb + (percent excess air)(air for perfect combustion, lb) =
14.6173 + (0.20)(13.6176) = 17.3408 lb (7.803 kilogram) of flue gas per
pound (kilogram) of oil burned with 20 percent excess air.

8. Compute the volume of the combustion products and the percent CO 2

The volume of excess air in the products of combustion is found by
converting from the weight to the volumetric analysis and correcting for
temperature as in step 4, using the air weight from step 2 for perfect

combustion and the excess-air percentage, or (13.6176)(0.20)(359/28.95)
3
3
(2.15) = 72.7 ft (2.058 m ). Add this to the volume of the products of
3
3
combustion found in step 4, or 387.82 + 72.70 = 460.52 ft (13.037 m ).
By using the procedure in step 5, the percent CO , wet basis = 55.0/460.52
2
= 0.1192, or 11.92 percent. The percent CO , dry basis = 55.0/(460.52 −
2
43.5) = 0.1318, or 13.18 percent.

Related Calculations. Use the method given here when making combustion
calculations for any type of fuel oil—paraffin-base, asphalt-base, Bunker C,
no. 2, 3, 4, or 5—from any source, domestic or foreign, in any type of furnace

—boiler, heater, process, or waste-heat. When the air used for combustion