The following data were obtained in a boiler trail:

Mass and temperature of feed water: 680 kg/hr and 20⁰C, Steam temperature and its pressure : 15bar and 300⁰C, Coal used and its calorific value: 98kg/hr and 26500kg/kg, Flue gas formed and its temperature at chimney: 18kg/kg of coal supplied and 300⁰C, Ash and unburnt coal in ash pit:

44kg/hr with 2200 kj/kg calorific value, Mean specific heat of flue gases and feed water: 1kj/kgK and 4.187 kj/kgK. If the ambient temperature in the boiler room is 28⁰C, Evaluate the:

i) Boiler efficiency,

ii) Equivalent evaporation from and at 100⁰ C,

iii) Percentage heat unaccounted,

iv) Draught produced in mm of water column if the height of chimney in 50 m.