In a boiler observations made were as: Rate of feed water per hour = 800 kg Temperature of feed water = 30°C Steam pressure = 12 bar Quality of steam = 0.95 Coal consumption rate per hour = 100 kg...

In a boiler observations made were as: Rate of feed water per hour = 800 kg Temperature of feed water = 30°C Steam pressure = 12 bar Quality of steam = 0.95 Coal consumption rate per hour = 100 kg Calorific value of coal = 32,000 kJ/kg Mass of ash and unburnt coal = 10 kg/h. Calorific value of ash and unburnt coal = 3,000 kJ/kg Quantity of flue gas/kg of coal = 20 kg Discharged gas temperature = 350°C Atmospheric temperature = 25°C Specific heat of flue gas = 1.03 kJ/kgK. Calculate:

 (a) boiler efficiency

 (b) percentage of heat loss in flue gas

 (c) percentage of heat loss to ash and unburnt coal

 (d) percentage of heat loss unaccounted for.