Question

a) explain the reason why heat is released when a hydrocarbon fuel is burned in a combustion chamber.

b) why excess air is necessary to use in an actual combustion? Explain

determine the following

c) the chemical reaction equation showing all reactants and products.

d) the required air to fuel ratio by mass, AFm (kg air/ kg fuel),

e) the rate of fuel comsumption if 300 kg of air per minute is supplied to the combustion, (kg fuel/min)

f) find if there will be condensation when the products are discharged to the atomsphere at 45 c, 101 kPa. Give your reasons.

molar mass: H: 1 amu, O: 16 amu, C: 12 amu, N: 14 amu

Answer 1

(a)

When Hydrocarbon fuel is burned in the combustion chamber, the bonds between the carbon-carbon and carbon-hydrogen elements get broken. Due to that break up of bonds, heat is generated. This is the reason why heat is released when hydrocarbon in burnt in combustion chamber.

(b)

Theoretically we don't need the excess air. But in real life practice, by providing theoretical can, chances of complete combustion is less. Due to that some unburnt fuel may go to the exhaust without being used. That's why we provide access air, so that the complete combustion will take place .