Quiz P-1
Multiple Choice
Identify the choice that best completes the statement or answers the question.
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1. The specific gravity of fuel oil is 0.924 at 35°C. Calculate the heating value of the fuel in KJ/kg.
a. 44,162
c. 45,252
b. 42,162
d. 43,852
2. A diesel electric plant in one of the remote provinces in the south utilizes diesel with an °API of 28
at 15.6°C. The plant consumes 680 liters of diesel fuel at 26.6°C in 24 hrs, while the power
generated for the same period amounts to 1980 KW-hrs. Determine the fuel rate in kg/KW-hr.
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a. 0.302
c. 1.065
b. 0.682
d. 1.293
3. A bituminous coal has the following compositions: C = 71.5%. O = 7.0% S = 3.6% W = 3.4% H = 5%, N =
1.3%, Ash = 8.2%. Calculate for complete combustion the theoretical weight of air required in kg air/kg coal.
a. 7.80
c. 8.90
b. 6.90
d. 9.80
4. What is the lower heating value of 29°API fuel in KJ/kg?
a. 43,750
c. 41,800
b. 45,500
d. 42,400
5. Fuel oil C12H26 burned in air at atmospheric pressure. The Orsat analysis of products of combustion yields.
CO2 = 12.8%, CO = 0.2%, O2 = 3.5%. N2 = 83.5%. Determine the percent excess air.
a. 8.42%
c. 17.35%
b. 14.67%
d. 12.25%
6. Calculate the calorific value of coal which has the following analysis: carbon 81%, Hydrogen 5%,
Oxygen 1.6%, Sulfur 1% and the remainder is ash.
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a. 34,410 KJ/kg
c. 32,135 KJ/kg
b. 36,546 KJ/kg
d. 38,194 KJ/kg
7. A typical industrial fuel oil, C16H32 has 20% excess air by weight. Assuming complete oxidation of the fuel,
calculate the actual air-fuel ratio in kg air/kg fuel.
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a. 14.75
c. 17.65
b. 16.75
d. 15.65
8. A diesel power plant uses fuel that has a density of 892.74 kg/m³ at 15.6°C. Find the heating value of the fuel
in KJ/kg.
a. 42,876
c. 43,285
b. 44,899
d. 45,126
9. Calculate the minimum volume of day tank of 28°API fuel having a fuel consumption of 1 kg/sec.
a. 95.7 m³
c. 79.4 m³
b. 97.4 m³
d. 91.7 m³
____ 10. A fuel gas has the following volumetric analysis: CH4 = 68%, C2H6 = 32%. Assume compute combustion
with 15% excess air at 101.325 kPa, 210C wet bulb and 270C dry bulb. What is the pressure of the water
vapour in kPa?
a. 26.4 kPa
c. 10.2 kPa
b. 18.1 kPa
d. 15.9 kPa
____ 11. A cylindrical tank 3 m long and 2 m diameter is used for fuel storage. How many days can the tank supply the
engine having 27°API with fuel consumption of 60kg/hr?
a. 4.26
c. 5.84
b. 7.85
d. 6.33
____ 12. There are 20 kg of flue gas formed per kg of fuel oil burned in the combustion of a fuel oil C12H26. What is the
excess air in percent?
a. 12%
c. 27%
b. 19%
d. 21%
____ 13. Find the theoretical air-fuel ratio of fuel oil C14H30.
a. 15.28
c. 16.22
b. 17.41
d. 14.91
____ 14. A diesel power plant uses fuel with heating value of 43,000 KJ/kg. What is the density of the fuel at 25°C?
a. 840 kg/ m³
c. 970 kg/ m³
b. 873 kg/ m³
d. 940 kg/ m³
____ 15. A diesel power plant uses fuel with heating value of 45,038.8 KJ/kg. What is the density of fuel at
30°C?
a. 0.888
c. 0.878
b. 0.858
d. 0.928
____ 16. A coal has the following ultimate analysis. C = 70%, N2 = 5%, S = 6% moisture = 8%, H2 = 3%, O2 = 4%, ash
= 5%. Using 25% excess air, determine the actual air fuel ratio.
a. 18.22
c. 11.46
b. 14.52
d. 8.04
____ 17. An unknown fuel has the following Orsat analysis: CO2 = 12.5%, O2 = 3.16%, CO = 0.3%, N2 = 84.1%.
Determine the actual air-fuel ratio kg air/kg fuel.
a. 21.64
c. 17.13
b. 19.62
d. 15.66
____ 18. Calculate the heating value of coal which has the following analysis: Carbon 81%, hydrogen 5% Oxygen
1.6%, sulphur 1%, and the remainder is ash.
a. 40,862 kJ/kg
c. 88,545 kJ/kg
b. 34, 409 kJ/kg
d. 36,143 kJ/kg
____ 19. A fuel oil is burned with 50% excess air and the combustion characteristics of the fuel are similar to C12H26.
Determine the volumetric analysis of CO2 in the product of combustion.
a. 12.18%
c. 14.75%
b. 9.14%
d. 8.66%
____ 20. A diesel power plant consumes 650 liters of fuel at 26°C in 24 hours with 28°API. Find the fuel rate in kg/hr.
a. 23.83
c. 5.84
b. 24.84
d. 22.85
Quiz P-1
Answer Section
MULTIPLE CHOICE
1. ANS: D
PTS: 1
2. ANS: A
PTS: 1
3. ANS: D
PTS: 1
4. ANS: D
PTS: 1
5. ANS: D
PTS: 1
6. ANS: A
PTS: 1
7. ANS: C
PTS: 1
8. ANS: B
PTS: 1
9. ANS: B
PTS: 1
10. ANS: D
PTS: 1
11. ANS: C
PTS: 1
12. ANS: C
PTS: 1
13. ANS: D
PTS: 1
14. ANS: C
PTS: 1
15. ANS: C
PTS: 1
16. ANS: C
PTS: 1
17. ANS: C
PTS: 1
18. ANS: B
PTS: 1
19. ANS: D
PTS: 1
20. ANS: A
PTS: 1