Given that:

In the firing system of a power plant, coal is completely burned with air (air ratio i = 1.5) at a constant pressure of p = 1 bar. The mass flow of the coal is m = 50 kg/s. The composition of the coal simplified as follows: &c = 0.82; H2 = 0.05; 6N2 = 0.03; (H2O = 0.10. The standard calorific value is hu,9 = 31.6 MJ/kg. The fuel (F) and the air are supplied to the combustion chamber with the temperature tp = tair = 25 C. The exhaust gas temperature is products = 125 C. a) Determine the amount of air required per kg of fuel and the combustion gas/fuel ratios y for all combustion gas components. b) Determine the heat flow emitted by the combustion. c) Determine the temperature to which the exhaust gas is cooled down when 30% of the water condensates. (5) d) Determine the amount of cubic meters of CO2 at normal conditions, which are released into the atmosphere per kilowatt-hour of useful power output, if the power plant has a thermal efficiency of nth = 0.36. (3) (6) (3) = Fluid properties: Fluid Molar mass average molar heat capacity 1125C 25C J/mol.K) [ M (g/mol) Enthalpy of vaporization of water at to = 25 C: r(to) = 2442.5 kJ/kg. Molar volume of ideal gases at normal conditions: Vmn = 22.414-10-?m?/mol H 02 N2 CO2 H2O(g) 12.01 2.02 32.00 28.01 44.01 18.02 29.7 29.1 39.1 33.9 Note: All gaseous components can be considered ideal gases Simplified composition of air: yo2 = 0.21; yn2 = 0.79. Vapor pressure of water: t/C 40 45 20 23.4 25 31.7 30 42.5 35 56.3 50 123.5 55 157.6 60 199.5 ps/mbar 73.8 95.8