ANSWER ALL
1. A quantity of coal used in a boiler had the followinganalysis: 82% C; 5% H; 6% 0; 2% N; 5% ash. The dry flue gasanalysis showed 14% CO2 and some oxygen. Calculate: (i) The oxygencontent of the dry flue gas; (ii) The A/F ratio and the excess airsupplied.
ANSWER (5.52%; 14.29/1; 31.8%)
2. The enthalpy of combustion of propane gas, C3H8, at 25 ?Cwith the H2O in the products in the liquid phase is – 50 360 kJ/kg.Calculate the enthalpy of combustion with the H2O in the vapourphase per unit mass of fuel and per unit amount of substance offuel. ANSWER (- 46 364 kJ/kg; - 2 040 030 kJ/kmol)
