5400 kg of steam is produced per hour at a pressure of 750 kN/m2 in a boiler when feed water at 41.5 C. The dryness fraction of steam at exit is 0.98. The amount of coal burnt per hour is 670 kg of calorific value 31000 kJ/kg. Determine the boiler efficiency and equivalent evaporation.

Wet coal amounting to 10000 ton/day is dried in an air dryer .The wet coal feed enters with 24% by mass of water and exits with 4%.The hot air used to dry the wet coal is fed at 40°C dry‐bulb temperature ,and 16°C wet‐bulb temperature .The moist air exits the dryer with 40% RH at 30°C. Calculate the amount of dry air atm 4/h at STP. Use psychrometric chart

During the expansion process of the ideal Ottocycle, the gas is a mixture whose volumetric composition is25 percent nitrogen, 7 percent oxygen, 28 percent water, and40 percent carbon dioxide. Calculate the thermal efficiency ofthis cycle when the air at the beginning of the compression isat 12 psia and 55°F, the compression ratio is 7, and the maxi-mum cycle temperature is 1600°F. Model the heat-additionand heat-rejection processes using constant gas properties thatare the average of the air and expansion gas properties.

A Stirling engine: (1) isothermal heat addition → (2) isochoric heat removal → (3) isothermal heat removal → (4) isochoric heat addition; uses one mole ideal rigid diatomic gas and operates between a hot and a cold reservoir at temperatures TH 600 K and To = 300 K, and a volume of V₁ = 1 L and V/₂ : = 4 L. Calculate the heat removal/addition in part (4) of the cycle. Select one: a. Q b. Q O c. Q O d. Q = = = = -6236 J 6916 J Q=-3458 J 6236 J